*Color-the color of the gem
not always reliable becasue colors vary, some colors are the same
*Streak-the color of the powder
more reliable than the real color because the streak is constent
*Hardness-a number to describe how hard a gem is
a stone is scratched by a higher number, and therefore scratches a lower number
1-Talc 6-Orthoclase
2-Gypsum 7-Quartz
3-Calcite 8-Topaz
4-Fluorite 9-Corundum
5-Apatite 10-Diamond
*Luster-the look of a gem
can be metallic or nonmetallic
nonmetallic luster includes:
vitreous-glassy
resinous-like resin
Adamantine-like a diamond
Pearly-internal reflection
silky-has fine, parellel fibers
earthy-dull and powdery
Tenacity-the way minerals are held together
Brittle-can be crushed into powder
Malleable-can be hammered into sheets
Doctile-can be made into wire
Sectile-can be easily cut
Flexible-can be bent
Elastic-can be folded, and then bounce back
Tough-will not break
*Cleavage-the way a gem naturally breaks
*Fracture-a break in some other direction besides the cleavage
*Specific Gravity- weight of mineral
weight of an equal volume of water
*Crystal Systems-the crystal shapes of a meneral
There are six types, the most common being cubic, tetragonal, hexagonal, and orthornombic
*Luminescence-the ability to glow in the dark
Florescence-glows under ultraviolet light
Phosphorescence-glows after ultraviolet light is turned off
Triboluminescence-glows after scratched in the dark
Thermoluminescence-glows when heated
Throughout history gems have been used as a source of magic. There was a gem for each month. It was considered good luck to wear the stone of your birth. This tradition has continued. Jewlry is often given containing one's birthstone.