Gemstone Guide

Alexandrite
Colors: Varies depending on the light - usually red in candle light, green in daylight, and blue to green in fluorescent light
Substance: A mineral (a type of chrysoberyl)
Moh’s scale of hardness: 8.5
Derivation: It was discovered on the birthday of Alexander II of Russia, and was named in his honor.

Amber
Colors: Light yellow to reddish brown
Substance: Actually, it is not a stone, but rather the hardened fossilized sap of pine trees
Moh’s scale of hardness: 2-2.5

Amethyst
Colors: Violet hues
Substance: Quartz
Moh’s scale of hardness: 7
Derivation: The Greek term "Amethystos," meaning "not intoxicated" - thought to ward off drunkenness, this also might mean pure.

Diamond
Colors: Come in all colors; commonly yellow, orange, brown to almost black, and colorless; and more rarer and more valuable are red, blue, green, and purple. Canary diamonds are deep yellow.
Substance: Precious gemstones made of highly-compressed carbon
Moh’s scale of hardness: 10 - the hardest!
Derivation: The Greek word "Adamas," meaning "unconquerable."

Garnet
Colors: Mainly hues of red, but can be any color but blue
Substance: Semi-precious silicate stones
Moh’s scale of hardness: 7-7.5
Derivation: The Latin word "granatum" meaning "pomegranate."
Scientific Formula: (Mg, Fe, Ca or Mn) with Al₂Si₃O₁₂

Opal
Colors: Mainly hues of red, but can be any color but blue
Substance: Semi-precious silicate stones of the quartz species
Moh’s scale of hardness: 5.5 – 6.5
Derivation: The Indian word for "stone."

Ruby
Colors: Range from the classic deep red to fuchsia to pink to purple to brown
Substance: Corundum family
Moh’s scale of hardness: 9
Derivation: The Latin word "rubeus," meaning "red."
Scientific Formula: (Al₂O₃)