Diamonds
All sorts of stuff about diamonds and
gems.
Diamonds are the hardest of all gemstones and the hardest
transparent substance. Natural diamonds are found in kimberlite
or lamproite pipes produced by volcanic magma millions of
years ago. Diamonds are a simple crystalline structure of
carbon produced by extremely high pressure and temperature.
The melting point of a diamond is 4,000 degree C or about
2.5 times higher than the melting point of steel. Gem quality
diamonds are rare; this helps to account for their value.
A rough diamond resembles a common pebble; but when properly
cut and polished by a skilled diamond cutter, its "fire"
or brilliance comes to life. Fire can be a seen as a flash,
spark, sparkle, or animation of light and colour caused
by the proportioning, angles and positioning of facets that
reflect and refract light inside the diamond. Facets must
be precisely cut so that light bounces freely inside the
diamond, and then exits through the crown or top, directly
to the eye of the viewer. The table, top or crown facet
is the largest and most important facet on a diamond. It
takes from several hours to several months to cut and polish
a diamond, depending on the size, shape and style of the
final product. During cutting and polishing, a rough diamond
will lose approximately 50% of its original weight.
More information is also to be found in
even more detail throughout this website in other places.
Diamonds & Gems
What is a gem? A gem is something which has Beauty, Durability,
Rarity, and Value.
A butterfly's wing has beauty, rarity, and value, but
no durability. A fine Opal may have the same colours and beauty.
It has rarity and value and is relatively durable (if not
abused), so it is considered a gem.
Gems can be classified as Organic and Inorganic. Most
gemstones are inorganic. Rubies, Sapphires, Topazes, etc.,
form as crystals of minerals and are inorganic. Some "gem
materials", however, are formed organically. Pearls,
Coral, Amber, Jet, Ivory, and Shell, are all organic gem materials.
We also have some gem materials that were organic, but come
to us as mineralized fossils. Ammolite, and Opalized bone
are examples of this.
It is important to know the difference between Natural,
Treated, Synthetic, and Imitation.
Natural gems have formed without any help from Man. They
may then be treated or untreated. Many natural stones are
treated in some way to bring out beauty that nature didn't.
Almost all Citrine on the market today was mined as Amethyst
and later heated to change it's colour from purple to yellow.
Blue Topaz is very rare in nature, but colourless topaz can
be irradiated and heated to give it the lovely blue colour
we're accustomed to seeing in jewellery. We will cover more
on treatments later.
Synthetic stones have all the physical, chemical and optical
properties of a natural stone, but they have been created
by Man. Some people use natural Sapphire, grind it up and
grow new crystals (recrystallize it). They may be tempted
to call the resulting stones "natural", but whether
the material came from nature or from a laboratory supply
house, the resulting stone is man-made and therefore "synthetic".
Imitation stones do not have the same properties as the
stone they are imitating. They just have the appearance. Rhinestones
are made of glass and have none of the distinguishing properties
of a Diamond, but they look like fine Diamonds.
You have probably heard gemstones referred to as "precious"
and "semi-precious". We no longer use those terms
because they can be misleading. A very fine Jade may be worth
many thousands of dollars. Many Black Opals cost between $1000
to $5000 per carat. A fine red Topaz of several carats may
cost $10,000. "Precious" stones (the big four) may
cost only a few dollars per carat. Poor quality Diamonds can
be bought for a few hundred dollars per carat and Rubies,
Sapphires and Emeralds may go for as little as two or three
dollars per carat.....hardly what we would call "precious".
When judging the value of a stone you will need to judge
the famous "4 C's". They are Colour, Clarity, Cut,
and Carat (weight). The 4 C's are basically a way of quantifying
BEAUTY. Durability and rarity are also important, but all
things being equal, beauty will make the difference between
high and low value in a gem.
If you compare two Sapphires side by side and they are
alike in all but color, the more beautiful colour will cost
more. If you compare two Topazes side by side, the more intense
colour will be more valuable.
People often ask: "Is the darker colour more valuable
than the lighter colour?" Here the proper way to find
the answer is to consider beauty. A stone that is too light
will not be very attractive. A stone that is too dark will
be dull and lifeless. The stone with an intense colour and
lots of flashes of light will be eye catching and very attractive.
That is the stone to look for.
Back to the 4 C's. If you have two stones of very lovely
intense colour, the stone with the most clarity will be the
most beautiful.
Between two stones with fantastic colour and flawless
clarity, the better cut of the two will show itself to best
advantage. A poorly cut flawless diamond will look like a
piece of cheap glass. Proper cutting makes the best use of
the optical properties of a stone. That is where the sparkle
and brilliance come from.
Finally, all things being equal, the larger stone will
be worth more. Some stones such as Amethyst and Citrine are
easy to find in large sizes so their "per carat"
price changes very little with size. Many stones, however,
are rare in larger sizes and the per carat price skyrockets
in larger stones. Alexandrite is a good example. Small gems
of under a carat can be expensive, but when they get over
a carat the price jumps even higher.
Keep in mind that stones form in nature, kind of like
in your backyard in the dirt. Nature isn't exactly a cleanly
swept laboratory so gems usually have various imperfections
or "inclusions" in them. When a gem crystal is found,
it may be easy to find a small area of perfection in it to
cut into a small gem. A large piece of perfection is much
more rare and so will be much more valuable.
COLOUR
We will begin by discussing colour in Diamonds. Diamonds
come in all colours. The most expensive stones in the world
are red Diamonds. A 1 carat red Diamond sold at auction for
approximately one million dollars!
Diamonds are usually thought of as being white, and the
less valuable ones as off-white. When a Diamond has enough
colour to be a "coloured" Diamond it is known as
a "fancy".
First we'll talk about white and off-white Diamonds. The
Gemological Institute of America has the most widely accepted
grading system for Diamonds. When they invented their system
they decided that since A, B, and C, had already been widely
used (and misused) for many things they would avoid those
letters and start with D.
Thus it is that a completely colourless (white) Diamond
is graded as a "D". Loose Diamonds up to G will
usually appear colourless. When they are set in yellow gold
you won't be able to judge colour. A stone with an easily
distinguished yellow tinge will be completely masked by yellow
gold.
D, E, and F stones are considered colourless. G, H, and
I are excellent and it really takes an expert to notice that
they have any colour to them. J, K, and L are noticeable but
accepted by most people. M through Z are obvious. After Z
begin the "fancy" yellow Diamonds, etc. From D to
Z the value goes down. After Z the value may go up again.
That depends on several factors. Rarity is one important factor.
Red is the rarest colour of Diamond. It is also attractive,
so it's the most valuable. Pink is next in line; it's really
just a light red. Blues, greens and yellows are very pretty
in the strong tones. An important thing to mention here is
the fact that Diamonds can be irradiated to achieve colour.
Very often, off colour Diamonds are subjected to either neutron
or electron bombardment to give them a fancy colour. Irradiated
Diamonds are usually a brighter and stronger colour than natural
fancies. The process is permanent and beautiful but irradiated
Diamonds are much less expensive.
You have probably heard the term "blue-white"
used in describing Diamonds. True blue-white Diamonds are
very rare, and the term is no longer used by good jewellers.
A blue white Diamond is one that is very white (D colour)
but in ultraviolet light (such as sunlight contains) it has
a slight bluish fluorescence. The term became very much abused
some years ago by unscrupulous dealers. Some dealers were
even calling K and L colour stones blue-whites!
Gems other than Diamonds are usually referred to as "coloured
stones". Many types of stones that we are used to thinking
of as being a particular colour, actually come in many colours.
Diamonds and Sapphires come in all colours. Sapphires (the
mineral corundum) are called Rubies when they are red. Garnets
are commonly red and brownish red, but they also come in orange,
pink, purple, and green. Fine green Garnets rival fine Emeralds
and are much more durable.
Topazes are well known in the yellow colour known as "Precious"
Topaz, but they also come in champagne, sherry, blue (from
very light to quite dark), pink (known as imperial Topaz),
and all the way to cherry red (rare and very expensive). Citrine
and Amethyst are two different colours of Quartz, which also
comes in light to dark smokey colour, often mistakenly called
Smokey Topaz. The mineral Beryl comes in several colours.
Green Beryl with the impurity chromium is called Emerald.
With iron as a colour causing impurity it will be blue and
is called Aquamarine. Pink is called Morganite, yellow is
called Heliodor, and colourless is called Goshenite. Spinel,
Zircon, and Tourmaline all come in many colours too.
CLARITY
The next of the four C's is clarity. It is normal for
stones to have small inclusions in them. Less inclusions mean
more value. The GIA definition of an internally flawless Diamond
is one in which "an expert, with a ten power magnification,
can not find any inclusions". Inevitably that same stone
may show many inclusions if the magnification is stepped up
enough.
Between two equal stones, the one with less inclusions
will be more attractive....that is where the value lies.
Most faceted stones are cut so that light will enter,
reflect, and come back out toward the eye, thus giving flash
and brilliance. Any inclusions in the stone will block that
light and prevent it from coming back out. Too many inclusions
will make a stone cloudy or dead looking. In Emeralds inclusions
are so frequent that they have been given the name "garden"
and they are viewed as normal. Flawless Emeralds are available
but they are more rare than other flawless stones and correspondingly
more expensive.
There are many kinds of inclusions. In Diamonds, dark
inclusions are usually called "carbon" spots, but
actually the only part that is not carbon is the inclusion.
The diamond is made of carbon and the inclusion is a foreign
particle contained in it. Garnet, Peridot, Pyrite, Hematite,
and Spinel are frequently found in diamonds. The inclusion
may look black, but it rarely is actually black and it's not
carbon. There are also white inclusions and they are usually
harder to spot. Being hard to see, they don't detract from
the stones value as much as an obvious dark inclusion.
When looking for inclusions in a stone, with or without
magnification, turn it in various directions and rock it slowly
back and forth, looking for any specks or spots, lines or
"feathers" inside the stone. Don't let dirt or lint
on the surface fool you. It's important to get the stone as
clean as possible or you are wasting your time. Whenever possible,
look at the stone from the bottom or "pavilion".
Especially in the case of Diamonds, it is much easier to see
inclusions from the bottom. A well cut Diamond is reflecting
a lot of light out the front and looking for inclusions is
a little bit like trying to read the writing on a car headlight
from the front while it's on.
Here is an approximation of the Gemological Institute
of America clarity grading criteria:
Using ten power magnification the inclusions seen are:
MINUTE "extremely difficult to see" VVS1
"very difficult to see" VVS2
MINOR "difficult to see" VS1
"somewhat easy to see" VS2
NOTICEABLE "easy to see" SI1
" very easy to see" SI2
OBVIOUS "Beauty or Durability somewhat I1
affected"
"Beauty or Durability seriously I2
affected"
PROMINENT "Beauty and Durability seriously I3
affected"
CUT
Our third C is cut. We are going to deal with faceted
stones, that is, stones cut with flat faces or facets. If
a stone is cut properly, light will enter it, reflect or bounce
around, and come back out to be seen and enjoyed. You may
notice that if you hold a piece of glass and tilt it, at a
certain point you can't see through it any more. You begin
to see a reflection. Inside a gemstone, the angle has to be
right for that light to reflect also. If the stone is not
cut properly, light will pass through instead of reflecting
back. That results in a transparent, washed out looking stone.
We call that "windowing".
In stones with high refractive indices, light is split
into it separate colors, like in a prism. That is why a Diamond
sparkles with all the colours of a rainbow. Again the stone
must be cut properly to take advantage of it's light splitting
properties.
When trying to judge a stone, you will get a big clue
about it's quality from how well it is cut. High quality material
is usually given the respect of good cutting. Poor material
is not usually considered worth the time, trouble, and extra
expense of careful cutting. Synthetics may be exceptions to
this because they are cheap and are often cut on machines
without worrying about loss of weight in cutting.
When viewing a round Diamond, the symmetry of the cut
is a big clue to its quality. the table (the flat top of the
stone) should be exactly the shape of a stop sign. If it is
lopsided or uneven, it is not well cut, and may not be a very
good stone. Small parallel grooves on the facets come from
polishing the stone in too much of a hurry and are called
"fast polish checks". Another big clue. If you hold
the stone in such a way as to see light reflected off of the
facet, you can usually see its symmetry and polish even without
magnification.
Look at the overall symmetry of the stone. Is a round
stone actually round or a little out of round? Is a square
stone even on all sides? Are the sides parallel? Is the table
centered at the top?
The main cuts you will see are Round, Oval, Emerald cut,
Marquise or Navette, Pear shape or Teardrop, and Baguette
(straight and tapered).
Different cuts have different values, varying with the
type of stone. Marquise cut Diamonds are the most expensive
for two reasons. There is a great demand for that cut and
the weight lost in cutting is greater than in other cuts.
The least expensive cut in large Sapphires is the oval cut.
A three carat round Sapphire is very hard to find but a three
carat oval is not.
ROUND BRILLIANT SINGLE CUT ANTIQUE CUSHION CUT
MARQUISE PEAR OR TEARDROP
(PENDELOQUE) OVAL
EMERALD CUT (OCTAGON) BAGUETTE TAPERED BAGUETTE
PRINCESS CUT RADIANT CUT SQUARE CUT
TRIANGLE TRIELLE TRILLIANT
OLD MINE CUT
Some other cut names and variations:
Radiant Trillion Princess Portuguese
Quadrillion Trilliant Kite Trapezoid
Quadrilliant Half Moon Hexagon 144 cut
Bagillion Rose cut Dutch Rose
CABOCHON CUTS are rounded, most often have flat bottoms
and don't have facets. Opals, and Tigereyes are usually cut
cabochon style. Cabochons are also cut in the same basic shapes
and would be called: round cabochon, square cabochon, oval
cabochon, etc.
CARAT (Weight)
The last of our Four C's is carat weight. One carat consists
of 100 points just as there are 100 cents in a dollar. That
means that a 25 point stone will be a quarter carat, a 66
point stone will be two thirds of a carat, etc. 5 carats equal
one gram, so a one carat stone weighs one fifth of a gram
(.20 grams). Don't get confused between Karat and Carat. Karat
refers to the purity of gold and we will cover that later.
Carat weight affects the value of a stone in three ways.
First, obviously a two carat stone (all things being equal)
will cost more than a one carat stone simply because there
is twice as much of it. Second, when cutting the rough stone,
it will always be easier to find a small piece of relative
perfection than a large piece. Third, some stones are rarely
found in sizes over a few carats, so, while small ones may
not be too expensive, slightly larger ones may suddenly be
very expensive.
Citrine, Amethyst, Smokey Quartz, and Blue Topaz are frequently
found as very large stones and the per carat price is usually
the same even in the larger sizes. The same quality of peridot
may be $10 to $15 per carat in a small size and $60 to $100
per carat in a three or four carat size.
WEIGHT FORMULAS
We will examine some very useful formulas for estimating
the weights of Diamonds. You may want to use these if you'd
like to estimate the weight of a mounted stone or maybe a
loose stone if you don't have a scale.
ROUND
Estimated weight = average diameter squared x depth x
.0061
OVAL
Estimated weight = average diameter squared x depth x
.0062
EMERALD CUT
Estimated weight = length x width x depth x adjustment
factor
Length-to-width ratio Adjustment factor
1.00:1.00 0.0080
1.50:1.00 0.0092
2.00:1.00 0.0100
2.50:1.00 0.0106
Length-to-width ratio = length divided by width
MARQUISE
Estimated weight = length x width x depth x adjustment
factor
Length-to-width ratio Adjustment factor
1.50:1.00 0.00565
2.00:1.00 0.00580
2.50:1.00 0.00585
3.00:1.00 0.00595
Length-to-width ratio = length divided by width
PEAR SHAPE
Estimated weight = length x width x depth x adjustment
factor
Length-to-width ratio Adjustment factor
1.25:1.00 0.00615
1.50:1.00 0.00600
1.66:1.00 0.00590
2.00:1.00 0.00575
Length-to-width ratio = length divided by width
Diamond Diameters and Corresponding Weights (These are
approximate)
1.15mm.. .005ct
1.35........ .01
1.55 ........02
1.90....... .03
2.10 ........04
2.30 ........05
2.70....... .06
2.90....... .07
3.10....... .10
3.50....... .15
4.10 ........23
4.50....... .33
5.13....... .50
5.88 ........75
6.50 .....1.00
6.90..... 1.25
7.40 .....1.50
8.20..... 2.00
GEM TREATMENTS AND ENHANCEMENTS
Most of the gems that you see on the market today have
been treated or enhanced in some way. Some people are disappointed
to learn this. The positive side is that because of these
treatments and enhancements, you can own and enjoy a fine
gem without having to be extremely wealthy or the equivalent
of royalty.
Here's a list of Treatments:
Heat
Radiation
Drilling (and Lasering)
Oiling
Sealing
Dyeing
Bleaching
Painting or Coating
Foilbacking
Fracture Filling
White Topaz is irradiated and then heated to create Blue
Topaz. Diamonds can have dark inclusions removed by laser
drilling. A very thin hole is drilled down to the inclusion
and acid is introduced to dissolve it. Now the same "inclusion"
is there but it is now a clear vacant space instead of a dark
(and easily seen) spot. The Diamond is now a bit more attractive
and thus easier to sell. Emeralds have been oiled since ancient
times. Different kinds of oils that have the same or almost
the same refractive index are used to fill cracks and fractures.
The result is that the cracks are now invisible, thus making
for a much more attractive gem. If coloured oils are used
then it is also dyeing. Many gems can be dyed as long as they
are either porous or cracked. Pearls are often bleached. Coral
is too. The backs of gems can be painted to make them seem
to be of strong, more intense colour than they really are.
Foilbacking is the mirror backing that makes rhinestones so
brilliant. Fracture filling (also called the Yehuda process
or clarity enhancement) makes cracks and fractures invisible
like in oiling except that the process is more durable. This
is used in Diamonds and is becoming common in Emeralds too.
In Diamonds the fracture fillers use very high heat and pressure
to force a special glass-like filler into the cracks that
reach the surface. In Emeralds a two part clear epoxy called
Opticon can be used.
Gem treatments are wonderful when they are used to enhance
the beauty of a gem. FULL DISCLOSURE is the LAW. These treatments
can also be misused to sell less expensive gems as their more
expensive cousins. Make sure you go to a jeweller or gem dealer
who keeps up with new developments and can tell the difference.
MISNOMERS
There are a number of incorrect names for gems and they
can be confusing and misleading. Here are a few of the more
common ones, and the actual stone referred to:
Arkansas Diamond Quartz crystal
Herkimer Diamond Quartz crystal
Balas Ruby Garnet
Colorado Ruby Garnet
Montana Ruby Garnet
Cape Ruby Garnet
Water Sapphire Iolite
Poor Man’s Tanzanite Iolite
Smoky Topaz Smoky Quartz
Indian Jade Aventurine
Manchurian Jade Soapstone
Nassau Pearl Conch Pearl
Hardness
An important property of gemstones is their hardness.
Diamond is the hardest and is rated a hardness of ten on the
"Mohs" scale. A man named Mohs rated different gem
materials according to their hardness relative to one another.
It's important to remember that hardness and toughness are
not the same. Diamond is the hardest, but Jade is the toughest!
Hardness is the measure of how easily something can be
scratched and on the Mohs scale any material with a lower
number can be scratched by any material with a higher number.
Here are the results of Mohs original research:
Mohs Hardness Scale
1 Talc 2 Gypsum 3 Calcite 4 Fluorspar 5 Apatite 6 Feldspar
7 Quartz 8 Topaz
9 Corundum (Sapphire & Ruby) 10 Diamond
This scale is not linear. As it
happens, Diamond is actually about 20 times harder than Sapphire.
A fingernail is about 2.5 and a steel file is about 6. Glass
is 5 so not only will a Diamond scratch glass, so will most
things. Opal at 5.5 to 6.5 will scratch glass and of course
C.Z. (Cubic Zirconia) at 8 to 8.5 will scratch it too!
GEMSTONE HARDNESS REFRACTIVE INDEX SPECIFIC
GRAVITY
Diamond 10 2.417 3.52 +-.03
Cubic Zirconia 8.5 2.15 5.80 +-.20
Corundum 9 1.762 to 1.770 4.00 +-.03
Chrysoberyl 8.5 1.746 to 1.755 3.73 +-.02
Beryl 7.5-8 1.577 to 1.583 2.67-2.84
Garnet 6.5-7.5 1.72 to 1.875 3.30-4.18
Opal 5.5-6.5 1.45 1.25-2.22
Ammolite 1.52 to 1.67 2.8
Peridot 6.5-7 1.654 to 1.690 3.31-3.48
Quartz 7 1.544 to 1.553 2.66 +-.01
Spinel 8 1.718 3.57-3.90
Topaz 8 1.619 to 1.627 3.53 +-.04
Tourmaline 7-7.5 1.624 to 1.644 3.01-3.21
Zircon 6-6.5 1.810 to 1.984 3.93-4.73
BIRTHSTONES
We are all familiar with the idea that there are birthstones
corresponding to the months of the year. There are also birthstones
for the days of the week, the seasons, the hours of the day,
and the signs of the Zodiac.
Here are the commonly accepted birthstones:
MONTHS OF THE YEAR Loose Gemstones
January..... Garnet Garnet Jewellery
February...... Amethyst Amethyst Jewellery
March..... Aquamarine, Blue Topaz, Bloodstone Blue Topaz &
Aquamarine Jewellery
April .....Diamond Diamond Jewellery
May..... Emerald Emerald Jewellery
June..... Alexandrite, Pearl, Moonstone Pearl Jewellery
July..... Ruby Ruby Jewellery
August..... Peridot, Sardonyx Peridot Jewellery
September..... Sapphire Sapphire Jewellery
October..... Opal, Rose Quartz, Tourmaline Opal Jewelelry
Tourmaline Jewellery
November..... Topaz, Citrine
December..... Blue Topaz, Blue Tourmaline, Blue Zircon,
Turquoise, Lapis Lazuli, and Tanzanite Loose Blue Topaz Blue
Topaz Jewellery
Blue Tourmaline Jewellery Tanzanite Jewellery
SEASONS OF THE YEAR
Spring... Emerald
Summer... Ruby
Autumn... Sapphire
Winter... Diamond
DAYS OF THE WEEK
Sunday... Topaz
Monday... Pearl, Crystal Quartz
Tuesday ...Ruby, Emerald
Wednesday... Amethyst, Lodestone
Thursday... Sapphire, Carnelian
Friday... Emerald, Cats-eye Chrysoberyl
Saturday... Diamond, Turquoise
HOURS OF THE DAY
A.M.... Smoky Quartz ......P.M.... Zircon
2 Hematite 2 Emerald
3 Malachite 3 Beryl
4 Lapis Lazuli 4 Topaz
5 Turquoise 5 Ruby
6 Tourmaline 6 Opal
7 Chrysolite 7 Sardonyx
8 Amethyst 8 Chalcedony
9 Kunzite 9 Jade
10 Sapphire 10 Jasper
11 Garnet 11 Lodestone
12 Diamond 12 Onyx
SIGNS OF THE ZODIAC
Aquarius (Jan. 21 - Feb. 21) Garnet
Pisces (Feb. 21 - Mar. 21) Amethyst
Aries (Mar. 21 - Apr. 20) Bloodstone
Taurus (Apr. 20 - May 21) Sapphire
Gemini (May 21 - Jun. 21) Agate
Cancer (Jun. 21 - Jul. 22) Emerald
Leo (Jul. 22 - Aug. 22) Onyx
Virgo (Aug. 22 - Sep. 22) Carnelian
Libra (Sep. 22 - Oct. 23) Chrysolite
Scorpio (Oct. 23 - Nov. 21) Beryl
Sagittarius (Nov. 21 - Dec. 21) Topaz
Capricorn (Dec. 21 - Jan. 21) Ruby
So, as you can see, you have many choices if you ever
want to buy or wear your birthstone. If you don't like "your"
birthstone, you can probably find another one that you do
like!
While we're on the subject of appropriate stones, here's
a list of appropriate Anniversary Gifts:
Year 1-11 Remembrance
12 Agate
13 Moonstone
14 Moss Agate, Ivory
15 Crystal Quartz
16 Topaz
17 Amethyst
18 Garnet
19 Hyacinth
20 China
25 Silver
30 Pearl
35 Coral, Jade
40 Ruby
50 Gold
55 Emerald
60 Diamond
CARE AND TREATMENT OF GEMS
Some gems are very durable and hardy; they will take a
lot of abuse without much damage. Others are easily chipped,
broken, scratched, or otherwise damaged.
To be on the safe side, all gems and jewellery should
be treated with care and respect.
CLEANING
To be on the safe side, let's start with some of the delicate
stones.
Stones to be careful of are: Amber, Coral, Ivory, Emerald,
Kunzite, Lapis Lazuli, Opal (especially doublets and triplets),
Pearls, Peridot, Shell Cameos, Tanzanite, Topaz, Turquoise,
and Zircon. (Zircon is not Cubic Zirconia.)
Strong cleaning solutions and heat may have a negative
effect on some stones or on their enhancements. Emeralds or
Rubies that have been oiled may lose their oil. Waxed or dyed
Turquoise may lose it's wax or dye and become colorless or
chalky. Doublet or triplet Opals may come apart. Pearls may
lose their luster.
If a stones enhancement is wiped out, it can often be
put back. Oiled stones can be re-oiled. Dyed stones can be
re-dyed. Chipped or cracked stones, however, can only be recut,
and pearls are gone forever.
Pearls are delicate and should only be put on after all
make up, perfume, and hair spray have been applied. Keep them
away from any chemicals. If they are worn against the skin,
they should be wiped carefully with a soft, damp cloth after
each use. If worn more or less frequently, they should be
restrung once or twice a year. If you see the string between
the pearls becoming dark or stained, get them restrung immediately.
That soiling may get into the pearls and become permanent.
Avoid temperature extremes, or rapid temperature changes
with most gemstones. Opals, for example, contain as much as
11 percent water, and freezing or boiling may destroy them!
There are many cleaning solutions available commercially,
but if you want to use something else, you can use detergent
ammonia from under your kitchen sink. Dip a toothbrush in
the ammonia and scrub your jewellery with it, then rinse it
well. Do NOT soak your jewelry in bleach or ammonia! For your
diamond and gold pieces, you can then boil them to get at
any dirt that your toothbrush was unable to reach. Diamonds
and gold can withstand a lot of heat, and boiling water can
only reach 212 degrees Fahrenheit, so those pieces will be
safe. Don’t do this with anything but Diamonds and gold!
Use a few drops of liquid dish detergent in the water to cut
grease and oil. Don't use too much or the pot will boil over
and make a mess on your stove, and don't forget and let the
pot boil dry, you will ruin your pot and possibly your jewellery
too.
NEVER put gems or jewellery in your microwave!
Here is a list of stones and their usual reactions, with
the following abbreviations:
Hardness H Toughness T
Reaction to boiling RB Reaction to ultrasonic RU
Reaction to steaming RS Reaction to acid RA
STONE H T RB RS RU RA
Alexandrite 8.5 v.good good good good good
Amber 2 poor poor poor poor poor
Amethyst 7 good fair fair good fair
Andalusite 7.5 good fair fair good fair
Aquamarine 8 fair fair fair fair good
Citrine 7 good fair fair good fair
Coral 3.5 poor poor fair fair poor
Cubic Zirconia 8.5 good good good good good
Emerald 7.5 poor poor poor fair poor
Diamond 10 good excl excl excl excl
Garnet 7 fair poor fair good poor
Hematite 6 fair good good good poor
Ivory 2.5 fair poor good fair fair
Jadeite 6.5 excl good good good poor
Kunzite 6.5 v.poor poor poor fair fair
Lapis Lazuli 5.5 poor poor good fair poor
Moonstone 6.5 poor poor fair fair poor
Nephrite 6.5 excl good good good poor
Opal 6 v.poor poor poor poor poor
Pearl 3 poor poor fair fair v.poor
Peridot 6.5 poor poor poor fair poor
Ruby 9 v.good good good good good
Sapphire 9 v.good good good good good
Shell cameo 3.5 poor poor poor fair v.poor
Spinel 8 fair fair good good good
Tanzanite 6.5 poor poor poor poor fair
Topaz 8 poor poor poor fair good
Turquoise 5.5 poor poor fair poor v.poor
Tourmaline 7.5 fair fair fair good fair
Zircon 6.5 poor poor poor fair fair
Opal Grading Opal Lore Opal Jewellery
The factors to consider in grading opals are: Size of
Colours, Number of Colours, Brightness/Life, Inclusions, Size,
and Cut.
An opal with large patches of colour is worth more than
an opal with small patches of colour. Several colours are
worth more than one colour. The brightness of the colours
is very important. Bright, vivid colours are more valuable
than muted, dull colours. Look for extinction. That is what
happens when you turn an opal different ways and the colours
can only be seen in some directions and not others. The more
life and less extinction an opal has, the more valuable it
is.
Inclusions (unless they are interesting, such as one that
is in the shape of Australia or something) detract from the
value.
A large opal (all things being equal) is worth more than
a small one up to a point. If an opal is too large to be useful
for anything, it is hard to sell, and thus less valuable.
A well cut opal will be symmetrical, well polished, and
not lumpy.
Many opals that used to be bright and lively, seem to
lose their colour. People say that they "dried out"
and that's why they lost their colour. Take a closer look.
Is the surface "frosty" looking? Opals are not hard
to scratch and frequent wearing will put a lot of tiny scratches
on the surface. Then it is like trying to see a rainbow through
frosted glass. The colours are there, but very dull. Polishing
the opal will bring the colours back to their vivid best.
Pearl Grading Pearl Lore Pearl Jewellery
Cultured pearls are the result of inserting a bead nucleus
into a pearl oyster and letting it coat that nucleus with
NACRE. Beads are cut from Mississippi River clams and sent
to Japan where they are used to culture Akoya (salt water)
pearls.
Pearls are graded on a number of factors similar to diamond
grading. The 4 C's of pearls would be Lustre and Orient (colour),
blemishes (clarity), shape (cut), and size (carat weight).
Lustre and Orient are the result of the thickness of the
Nacre. Nacre is the coating that the oyster deposits over
the bead nucleus inserted by the oyster farmer. The thicker
it is, the more of a "sheen" the pearl will have.
There is a brightness and surface play of colour somewhat
like the sheen of an oil slick. The finer the pearl the sharper
a reflection will be on its surface. A poor pearl will be
dull and show little or no reflection. On a very fine pearl,
you may be able to see yourself clearly. Pearls come in all
colours.
It is normal to have some blemishes on the surface of
the pearl. More blemishes mean less cost. Evenness of colour
is also important.
Pearls come in a variety of shapes. Freshwater or Biwa
pearls look like Rice Krispies although now the Chinese have
developed round freshwater pearls. "Round" pearls
are classified as round, semi-round, and baroque.
It is hard to find perfectly round pearls. Matching size
and color is also time consuming so a well matched strand
can be costly.
Crystals and Healing
Here are a few beliefs about what healing powers area
associated with certain crystals.
Amethyst: Acne, adenoids, alcoholism (and/or getting drunk),
cankers, eczema and gum ailments.
Azurite: Asthma (and other respiratory ailments) and tonsillitis.
Cerussite: Abscesses, conjunctivitis & other eye ailments,
headaches, emotional stress, and hyperactivity.
Cinnabar: Bladder ailments, back pain, appendicitis, leg circulation
and hemorrhoids. (WARNING! Cinnabar contains mercury! I don’t
recommend handling it and especially don’t heat it, boil
it or eat or drink anything that has come in contact with
it!)
Malachite: Bronchitis, diabetes, heart ailments, flu and pleurisy.
Pyrite: Circulatory problems, liver and kidney aliments, dry
skin, gastritis, and flatulence.
Australian Aborigines, among other indigenous populations,
also still use Crystals for medicine. Their favorites are
Multi-Colour Crystals, as they believe that they hold the
energy of the Rainbow Serpent, acting as a bridge between
the spirit and physical worlds.
Uncut Diamond
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Click onto each of the 4 "C's"
to learn about qualities to consider when evaluating
a diamond.
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