Creedite Value, Price, and Jewelry Information

Creedite: Chihuahua, Mexico (0.96). Photo © Joel E. Arem, PhD, FGA. Used with permission.

Creedite

Probably fewer than a dozen creedite gems have ever been faceted. This rare mineral is rarer still as a cuttable crystal. Too soft to wear, this strictly collector’s gem occurs in attractive white, purple, and orange colors.

Creedite Information

Data Value
Name Creedite
Formula Ca­3AI2(SO4)(F,OH)10 • 2H2O.
Etymology After the type locality, Creede Quadrangle, Colorado.
Occurrence Fluorite-rich hydrothermal mineral deposits.
Colors Colorless, white, rose to lilac or purple, orange.
Fracture Conchoidal
Hardness 4
Cleavage Perfect 1 direction
Crystallography Monoclinic. Crystals short, prismatic; also radial clusters.
Refractive Index 1.461-1.485
Birefringence 0.024
Dispersion Moderate
Luminescence Medium white to cream color (SW); bright white to cream (LW).
Luminescence Present Yes
Luminescence Type Fluorescent, UV-Long, UV-Short
Absorption Spectrum Not diagnostic.
Optics a = 1.461; β = 1.478; γ = 1.485. Biaxial (-), 2V = 64°.
Optic Sign Biaxial -
Luster Vitreous.
Specific Gravity 2.71-2.73
Transparency Transparent to opaque.
creedite crystal - Chihuahua, Mexico

“Creedite,” West Camp, Santa Eulalia, Chihuahua, Mexico, 4.3 x 3.2 x 2.7 cm, amethystine colored crystals. © Rob Lavinsky, www.iRocks.com. Used with permission.

Comments

Transparent colorless and purple material from Chihuahua, Mexico has yielded rare facetable creedites. In recent decades, new sources have produced more material in more colors, such as orange.

Synthetics

No known synthetics or enhancements.

Sources

The classic source for gemmy material, Santa Eulalia, Chihuahua, Mexico produces crystals up to 1 inch long.

Durango, Mexico has produced stunning, bright orange crystals.

Other notable sources include:

  • United States: Darwin, California; Creede, Colorado (in cavities in rock with fluorite and barite); Wagon Wheel Gap, Colorado (in a fluorite-barite mine); Granite, Nevada.
  • Colquiri, Bolivia; China (colorless); Kazakhstan (purple).
creedite - Durango, Mexico.

“Creedite,” Abasolo Mine, Navidad, Durango, Mexico, 5.1 x 4.4 x 4.0 cm. © Rob Lavinsky, www.iRocks.com. Used with permission.

Stone Sizes

Any faceted gems are very small, usually less than 1-2 carats.

  • Private Collection: 0.96 (purple, Chihuahua).

Care

You’re more likely to find creedite gems in a mineral collection, if at all, than a jewelry collection. With perfect cleavage and a low hardness of 4, creedites wouldn’t make durable jewelry stones. A sensitivity to acid makes it inadvisable to wear or handle these gems for long periods. See our gemstone jewelry care guide for cleaning recommendations.

creedite - Kazakhstan

“Creedite,” Akchatau Mine, Karaganda Oblast, Kazakhstan, 3.2 x 2.3 x 1.9 cm. © Rob Lavinsky, www.iRocks.com. Used with permission.

by Joel E. Arem, Ph.D., FGA