Aquamarine

Birthstone: March
Chakra: Throat, Heart
Element: Water
Known As: Stone of Courage & Protection
Planet: Neptune
Rarity: Common
Resonant Number: 1
Zodiac: Aries, Gemini, Pisces

Category: Cyclosilicate
Crystal Class: Dihexagonal Dipyramidal
Crystal System: Hexagonal
Dana Classification: 61.01.01.01
Empirical Formula: Be₃Al₂Si₆O₁₈
Name: Aquamarine
Strunz Classification: 9.CJ.05
Synonym: Beryl
Unit Cell: a = 9.21 Å, c = 9.19 Å; Z = 2

Birefringence: δ = 0.0040–0.0070
Cleavage: {0001} Imperfect
Common Colors: Blue, Green, Light Blue
Crystal Habit: Columnar, Crystalline, Prismatic
Diaphaneity: Transparent, Subtranslucent
Formula Mass: 537.50 g/mol
Fracture: Brittle, Conchoidal
Luster: Vitreous, Resinous
Mohs Hardness: 7.5 - 8
Optical Properties: Uniaxial (-), e=1.564-1.595, w=1.568-1.602, bire=0.0040-0.0070
Refractive Index: nω = 1.564–1.595, nε = 1.568–1.602
Streak: White
Tenacity: Brittle