Citrine

Citrine is rare in nature. Its attractive color, plus the durability and affordability it shares with most other quartzes, makes it the top-selling yellow gem stone.

MINERAL: Quartz
COLORs: Yellow to orange to orangy red
REFRACTIVE INDEX: 1.544 to 1.553
SPECIFIC GRAVITY: 2.66 (+0.03/-0.02)
MOHS HARDNESS: 7