Creedite Gem Guide and Properties Chart

Creedite

By Tim Matthews, JD, FGA, GG, DGA,
CEO and President of JTV (retired)

Published: June 2014

Modified: October 2021

Creedite was discovered in the Colorado Fluorspar Co. Mine in 1916. The mine is located in the Creede Quadrangle, Mineral County, Colorado and this was the inspiration for its name. It comes in colorless, orange, purple, violet, and white prismatic crystals that sometime radiate from the base.

General Information

Classification
Optical Properties
Characteristic Physical Properties
Chemistry & Crystallography

Common Name

Creedite

Species

Creedite

Transparency

Opaque-Transparent

Dispersion

Strength: Strong Fire

Refractive Index

1.461-1.485

Birefringence

0.024

Optic Character

Biaxial

Optic Sign

Negative

Hardness

Streak

white

Specific Gravity

2.713-2.730

Toughness

Poor

Luster

Vitreous

Fracture

conchoidal

Cleavage

perfect

Chemical Name

calcium aluminium sulfate fluoro hydroxide

Chemical Formula

Ca₃SO₄Al₂F₈(OH)₂*2H₂O

Crystal System

Monoclinic

Chemistry Classification

Halide

Creedite Colors

Blue
Colorless
Orange
Purple
White

Countries of Origin

Greece; Unknown; China; United States of America; Italy; Mexico; South Africa; Australia; France; Kazakhstan; Tajikistan; Bolivia (Plurinational State of)

Care

Creedite is brittle so please take care when handling specimens.