Trapiche Emerald

By admin | No Comments

Refractive Index : 1.583-1.577 + 0.017 – 0.017

Optical Characteristic : DR, U-

Specific Gravity : 2.72 + 0.18 – 0.05

Formula : Be3AI2Si6O18

Crystal System : Hexagonal

Variety/Species : Trapiche emerald

Species/Group : Beryl

Birefringence : 0.005 to 0.009

Dispersion : 0.014

Hardness : 7.5 to 8

Toughness : Poor to good

Ultrasonic : Never

Steam : Never

UV Long : Inert to strong

UV Short : Inert to strong

Pleochroism : 2 colors

Strength : Moderate to strong

Pleochroism Colors : Moderate to strong : Green/blue green

Heat : May fracture

Acids : Avoid hydrofluoric acid

Light : Stable

Polish Luster : Vitreous

Fracture : Conchoidal

Fracture Luster : Vitreocs to resinous

Clarity Type : III

Tones : 3-8

Saturations : 2-5

Cause of Color : Usually chromium, sometimes vanadium, or both

Enhancements : Oiling, opticon

Cleavage : Indistinct

Color Range : strongly, bluish green, green .

Transparency : Transparent to translucent (highly included stones)

Phenomena : None

Separations : Trapiche Emerald from-
Flux synthetic emerald (except Gilson Type III) : magnification, RI ,birefriegence, fluoresence, SG

Gilson Type III: Magnification, spectrum (possibly)

All triplets : Magnification, immersion, RI (possibly)

Hydrothermal synthetic emerald : Magnification, fluorescene

Hydrothermal overgrowth/sandwich : Magnification, fluorescene, immersion

Dioptase : RI, birefringence, SG, cleavage, magnification

Identifying Characteristics and information
Colombian emeralds are characterized by 6 green to black spoke or arms .
Albite or carbonaceous inclusions cause the areas between the arms to appear black or grayish.
Pyrite, calcite and mica inclusions, 3-phase inclusions.

Spectral Data
Lines at 6830 and 6805. Less distinct lines at 6620, 6460.

Trade Names and Misnomers

Tags: Hexagonal, Trapiche Emerald