黃水晶

• The variety of the mineral quartz; hexagonal (trigonal) crystal system; chemical composition SiO2
• transparent 
• yellow to orange to brownish orange

Identification:

• Optic Character: DR, uniaxial, positive 
• Refractive Index: 1.544-1.553 (very constant)
• Birefringence: .009 
• Dispersion: .013 
• Pleochroism: very weak, different tones of yellow or orange 
• Ultraviolet Fluorescence: inert 
• Absorption Spectra: not diagnostic 
• Cause of Color: iron 
• Specific Gravity: 2.66 (+.03, -.02) 
• Polish Luster: vitreous 
• Fracture: conchoidal
• Luster: vitreous 
• Cleavage: none 
• Identifying Characteristics: color zoning, liquid, 2-phase, and 3-phase inclusions, negative crystals, may show bull’s-eye or Airy’s spiral optic figure. 
• Hardness: 7
• Toughness: good 

Enhancements:

• Method: heat treatment

Effect: produces citrine from amethyst 

Prevalence: common

Detection: undetectable 

Stability: excellent 

Birthstone Designation(s): 

November, 13th wedding anniversary 

Major Source: Brazil. Others: Bolivia, Spain.

Stone information is reference from

Gem Reference Guide, Published by GIA. ISBN 0-87311-019-6

Gemstones of the World, Published by Sterling Publishing Co., Inc NY, ISBN 1-4027-4016-6

Encyclopedia of GEMSTONE, Published by ISHINSHA CO., LTD. ISBN 978-986-251-831-1