Tourmaline
Consumer Information
What color is it?: Tourmalines come in all colors of the rainbow. No gem family is more diverse than tourmaline.
Pink
tourmaline crystal and faceted stones
What is the story behind this gemstone?: Tourmalines have been used by royalty for years to show wealth. For many centuries fine quality green tourmalines were mistaken for exceptional emeralds. And no gemstone will offer as many vivid colors, and be as durable and long wearing as tourmaline.
Can I wear it everyday?: Absolutely. One of the best gemstones for everyday wear.
Is it
expensive?: Tourmalines will run from
very affordable to moderately expensive depending on the color
and quality.
Is it a birthstone?: Not exactly. But if you do not like the birthstone you have, you can always find that same color somewhere in the tourmaline family.
What do I need to know before going shopping?: Be sure and shop with a qualified professional jeweler when shopping for tourmalines. Look for a store that carries a lot of colored gemstones, and a store who has a trained gemologist, to be sure that you are getting the quality and the stone you are paying for.
An unusual burnt orange color tourmaline set in a 4 prong pendant.
...
General
Information
Tourmaline crystal in matrix shown above
Source: Brazil, United States (various locations)
Chemical: Varies with variety of stone
Formation: In pegmatite dikes.
Crystal System: Classic trigonal crystals. Note rounded triangular sides below. Prismatic crystals.
Unusual Properties: Bi-color (watermelon) tourmalines occur in a number of color combinations. Also cat's eye or chatoyancy is also noted in tourmaline. Note: Care should be taken when cutting toumaline as light passing down, or parallel to, the long "C" axis is poorly tranmitted. This requires that tourmaline be cut with the table parallel to the "C" axis to obtain the best result for color. Otherwise the stone will be dark. This is why tourmaline is so often seen as long rectangular shapes when faceted. Please see the photo's below for demonstration of light reaction to the different axis directions.
Bi-color
tourmaline crystal and faceted stones
Light transmitted perpendicular to "c" axis..and
parallel to "c" axis.
Faceted tourmaline showing color transmission when
properly cut. .......
All photos by Your Gemologist
Gemological Information
RI: 1.634 - 1.643
Birefringence: .009
Optic Character: U-
Specific Gravity: 3.06
Hardness: 7 - 7.5
Transparency: Opaque - TP
Special Identifying Properties and Tests: Would somebody please tell the GIA Graduate Gemologists that pink tourmaline and pink topaz test very close together on a refractometer! But tourmaline will float in a 3.32 methylene iodide solution while pink topaz will sink. This is a diagnostic test to tell them apart. Please do not stop just with just your refractometer. Many are causing so many problems for the pink topaz market because not enough tests are done before the ID is put forth. Remeber that gemological identification protocal requires that you find out what it is not...not what it is. If you have two stones giving you the same reading you still have not made a proper identificiation. You must test further.
Synthetics: Tourmaline is too complicated to synthesize as of this date.
Imitations: Many.