Impregnated Turquoise | Gemopedia

As it occurs naturally, turquoise is a soft mineral that is easily scratched. Its porous nature can allow the absorption of oils and fluids that can discolor it over time. To improve its durability and appearance, much of the turquoise on the market today is stabilized. One popular method of stabilization is impregnation, which fills the porous areas with a colorless agent, usually plastic.
Alternate
Names
Impregnated Turuqois
Colors
Slightly Yellowish Green If Wax Impregnated, Greenish Blue If Impregnated With Plastic

Impregnated Turquoise Classification

Common Name

Impregnated Turquoise

Species

Turquoise

Variety

Colors

Slightly Yellowish Green If Wax Impregnated, Greenish Blue If Impregnated With Plastic

Alternate Names

Impregnated Turuqois

Gemstone Groups

Key Separations

RI, magnification, SG, spectrum and acrid smell and sweating effect if hot point test is used

Comments

If stones are heavily treated the RI can be as low as 1.56. If SG is below 2.60 and has fine color it is a fine indication that some impregnation has occurred. Some heavily treated material can have SG's as low as 1.80 to 2.00.

Impregnated Turquoise Optical Properties

Transparency

Semitranslucent - Opaque

Refractive Index

1.6-1.61

Birefringence

0.04

Optic Character

Biaxial

Optic Sign

Positive

Polariscope Reaction

Aggregate (AGG)

Fluorescence

SWUV: Inert
LWUV: Inert to weak greenish yellow

CCF Reaction

Pleochroism

None

Dispersion

Strength: none

Comments

Impregnated Turquoise Chemistry & Crystallography

Chemical Name

hydrated copper aluminum phosphate

Chemical Formula

CuAl6(PO4)4(OH)8-5H2O

Synthesis

Crystal System

Triclinic

Classification

Phosphate

Nature

Natural

Crystallinity

Aggregate

Comments

Impregnated Turquoise Characteristic Physical Properties

Hardness

5-6

Streak

Specific Gravity

2.5-2.6

Toughness

Varies

Inclusions

Impregnated turquoise often has brown, gray or black matrix that is recessed below polished surface. Stones will have a higher luster than natural turquoise. Stones may contain pyrite or calcite inclusions. Stones can have a speckled appearance similar to the "cream-of-wheat" effect if wax impregnated.

Luster

Vitreous

Stability

Fracture

Conchoidal, Granular

Cleavage

None

Comments

JTV on Google+
0 Items
My Wish List
Close
Item
Description
Qty.
Price


Estimated Order Total:
0
Total Due Today:
0
Close
Item
Description
Qty.
Price


Page of 1