TURQUOISE

Seaman Schepps Soho Earrings with white topaz and turquoise in 18K gold

Species:  Turquoise
​​Mohs Hardness:  5 to 6 out of 10
Color:  Light to medium blue, greenish blue to green.  Sometimes mottled, and might show dark patches or veins of matrix, often slightly recessed beneath the polished surface.
RI:  1.610 to 1.650 (usually a 1.61 spot reading)
SR/DR/AGG:  AGG
Spectrum:  Occasionally shows weak to medium bands at 420 and 432nm (432nm band is stronger).  Might also show a weak band at 460nm.
Fluorescence:  Inert to weak greenish yellow under LW.  Inert to SW.
SG:  2.74 (+0.14 / -0.36)
Routine Treatments:  Staining, impregnation with waxes/resins, Zachery treatment
Additional Enhancements:  Dyeing

Turquoise Facts

Victorian Era crescent brooch set with multi-colored turquoise

Turquoise is a very popular, opaque gem that ranges in color from greenish blue to blue-green, to green, often containing natural matrix.

Matrix refers to the natural host rock in turquoise.  The amount of matrix present in turquoise varies from none at all to the very attractive, spiderweb turquoise.

Turquoise is one of the first gems used for personal decoration, used by Egyptian rulers as far back as 5500 BC.

King Tutankhamen's funeral mask contained a turquoise inlay.

​Turquoise is used in all types of jewelry, ranging from top tier designer pieces to handmade, Native American jewelry.

Turquoise is a December birthstone and is the 11th wedding anniversary gemstone.


TURQUOISE TREATMENTS:

• Dyeing:  Turquoise's high porosity makes for easy absorption of dyes, which enhance the gem's color.

• Impregnation:  The turquoise is impregnated with a foreign material such as plastic, wax, silicone, or polymer.  This process reduces the porosity of the gem, making it less susceptible to discoloration from grease, oils, hair products, etc.

 • Zachery-Treated:  The Zachery Method is a type of enhancement that can also reduce porosity and improve color.  Zachery-treated turquoise is currently undetectable by standard gemological equipment.

Turquoise Gallery

All photos are courtesy of Scott Papper, GG, ASA, CMA, RGA, AJP, CSMP, CSSP