Assorted:
Conversion Tables, Equivalents,
Mohs' Scale

Gem Weight and Measurement Conversions - Mohs Table

GEM - DIA. WT. - CONVERSION FACTOR (Multiply the diamond wt. listed for each stone size by the conversion factor to know the approximate wt. of a particualr stone)


Alexandrite= Dia. Wt. X 1.06
Amethyst= Dia. Wt. X .76
Aquamarine= Dia. Wt. X .78 (+/-3%)
Citrine= Dia. Wt. X .76
Emerald= Dia. Wt. X .78 (+/-3%)
Garnet= Dia. Wt. X 1.06 (+/-12%)
Peridot= Dia. Wt. X .96 (+/-2%)
Ruby= Dia. Wt. X 1.14
Sapphire= Dia. Wt. X 1.14
Topaz= Dia. Wt. X 1.0 (+/- 1%)
Tourmaline= Dia. Wt. X .88 (+/- 3%)

Carat Conversion (Approximate)
1 carat = 0.20 grams
1 carat = 0.1287 pennyweight
1 carat = 0.0064 ounces Troy
1 carat = 0.0071 ounces Avoirdupois (Adp)
1 gram = 5 carats
1 pennyweight = 7.776 carats
1 oz. Troy = 155.5 carats
1 oz. (Adp) = 141.75 carats
1 lb. (Adp) = 2267.95 carats

EQUIVALENTS
1 millimeter = 0.03937
1 inch = 25.4 millimeters
In Fractions= Decimals= Millimeters
1/64in= 0.01563= 0.39688
1/32in= 0.03125= 0.79375
1/16in= 0.0625= 1.5875
1/8in= 0.125= 3.175
1/4in= 0.250= 6.35
1/2in= 0.500= 12.7
1in= 1.000= 25.4

MOHS TABLE of Hardness (Modified) Approximate
STONE HARDNESS
Amethyst 7.0
Apatite 5.0
Aquamarine 7.5
Chrysoprase 6.5 - 7.0
Citrine 7.0
Corundum 9.0
Diamond 10.0
Emerald 7.5
Garnet 7.0 - 7.5
Kunzite 6.0 - 7.0
Morganite 7.5 - 8.0
Opal 5.0 - 6.0
Peridot 6.5 - 7.0
Quartz 7.0
Rhodolite Garnet 7.0 - 7.5
Ruby 9.0
Sapphire 9.0
Spinel 8.5
Tanzanite 6.5 - 7.0
Topaz 8.0
Tourmaline 7.0 - 7.5
Zircon 6.5

Note: "The Mohs scale is a scratch test, not a durability test