Almandite Garnet

• Almandite or almandine is a mineral species in the garnet group; cubic crystal system; chemical composition FeAL (SiO4)3 
• transparent to semi-translucent (for very dark stones)
• reddish orange to red, slightly purplish red to reddish purple: typically dark in tone 

Identification

• Optic Character: SR, often ADR 
• Refractive Index: 1.790 (3.030) 
• Birefringence: none
• Dispersion: .024 HAYA
• Pleochroism: none 
• Ultraviolet Fluorescence: inert 
• Absorption Spectra: usually three strong bands at 504, 520, and 573 nm but may also show fainter lines at 423, 460, 610, and 680-690 nm
• Cause of Color: iron 
• Specific Gravity: 4.05 (+.25, -.12) 
• Polish Luster: vitreous to subadamantine 
• Fracture: conchoidal
• Luster: greasy to vitreous 
• Cleavage: none; may have indistinct parting 
• Hardness: 7 to 71/2 
• Toughness: fair to good 

Birthstone Designation(s)

January, Aquarius (approximately Jan. 20 – Feb. 18), 11:00 am, 2nd wedding anniversary 

Major Sources: India, Sri Lanka, Madagascar, Brazil. Others: Greenland, Kenya, Pakistan, Tanza-nia, US 

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