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Gemstones
Notes,
Comments, and Definitions of Techinical Specifications:
* Man made material
** Not found in nature. Created by heating
amethyst and yellow quartz
"v" = Very
"Disp." = Dispersion: Ability to
split or divide white light into various colors like the rainbow.
"Pleochro." = Pleochroism :
Ability to have different color or depth of color when viewed in
different directions.
"Refraction" : A ray of
light leaves one medium (for instance air) and enters into another (such
as a gem) at a different angle. "Refraction" is the amount of
the difference of the two lines of the same ray of light. Similar to a
pole partly in water and partly out of water. The pole appears to bend
in the water where the water and the air meet.
Refractive Index The amount of refraction defined as the proportional
relationship between the speed of light in air to that of the gemstone,
crystal, or gem rough. Can be determined by a refractometer
"Double" = Double Refraction:
The ability to have one ray of light split into two rays of light.
Therefore, having two refractive indices. It is expressed as the
differance between the highest and lowest refractive indices. An expert
lapidarist can situate the cut of the stone in such a way to almost
alleviate the blurred affect or the doubling effect of facet edges or
images as one looks into or through double refractive stones. Can be
determined with a polariscope.
- Gemstones
having a Moh's Hardness of less than 5 are too soft for jewelry and
are basically collector stones.
- About
170 gemstones are listed above. Many not listed are rare collectible
gemstones.
- Please
notify us about any errors or additional information.
- Please
help us add to the list. If you know of a gemstone not listed,
please provide us with the information and documentation.
- Thank
you!
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