Crystal Hemimorphite

Chemical Formula

Zn₄Si₂O₇(OH)₂ · H₂O

Composition

Basic hydrous zinc silicate

Color

White, colorless, beige, yellow, light brown, blue. Rarely greenish or yellow.

Streak

Colorless

Hardness

4.5 - 5

Crystal System

Orthorhombic

Crystal Forms 
and Aggregates

Crystals are flattened prismatic and tabular, and are usually in platy groupings. Also bladed, in fan shaped groupings, radiating, acicular, coxcomb, in rosettes, and drusy. Crystals grow in distinctive hemimorphic habits. Most commonly in globular form such as botryoidal, mammilary, and stalactiticgroupings. 

Transparency

Transparent to translucent

Specific Gravity

3.4 - 3.5

Luster

Crystals are Vitreous to adamantine. Globular forms are vitreous, waxy, silky, or dull.

Cleavage

1,1

Fracture

Subconchoidal to uneven

Tenacity

Brittle

Other ID Marks

1) Strongly pyroelectric.

2) May fluoresce pale orange in longwave ultraviolet light.

In Group

Silicates; Sorosilicates

Striking Features

Crystal forms and habits, and mode of occurrence

Environment

In the oxidation zone of hydrothermal replacement deposi

Rock Type

Sedimentary, Metamorphic

Popularity (1-4)

2

Prevalence (1-3)

2

Demand (1-3)

1