Crystal Covellite

Chemical Formula

CuS 

Composition

Copper sulfide, sometimes with some iron

Variable Formula

(Cu,Fe)S 

Color

Dark metallic-blue to dark gray. Highly iridescent bright blue; sometimes also purple, red, and yellow.

Streak

Dark gray to black

Hardness

1.5 - 2

Crystal System

Hexagonal

Crystal Forms 
and Aggregates

Crystals, which are uncommon, are mostly in thin tabular hexagonal plates. They are usually bladedand doubly terminated. Most often platy, grainy, foliated, as coatings, in veins, and massive.

Transparency

Opaque

Specific Gravity

4.6 - 4.8

Luster

Metallic

Cleavage

1,1

Fracture

Uneven

Tenacity

Brittle but slighty sectile. Thin flakes are flexible but not elastic.

In Group

Sulfides; Simple Sulfides

Striking Features

Iridescent color and habits

Environment

In hydrothermal replacement ore deposits and in skarns.

Rock Type

Igneous, Sedimentary, Metamorphic

Popularity (1-4)

3

Prevalence (1-3)

2

Demand (1-3)

2