Natrolite

Real mineral · uncommon · Na₂[Al₂Si₃O₁₀]•2(H₂O)

A sodium zeolite in radiating sprays of fine needles lining gas cavities in basalt. Heated, it froths and fuses as the loosely held water is driven out of its open framework.

Identity

Formula

Na₂[Al₂Si₃O₁₀]•2(H₂O)

Chemical class

silicate

Mineral group

Analcime, Heulandite, Stilbite

Also known as

Needle zeolite

Crystallography

Crystal system

orthorhombic

Habits

acicular, prismatic, fibrous, massive

Fracture

uneven

Physical properties

Mohs hardness

5.5

Density

2.25 g/cm³

Luster

silky, vitreous

Colors

white, colorless, red, yellowish white, reddish white

Streak

white

Transparency

transparent, translucent

Geology

Origins

igneous, hydrothermal

Host rocks

basalt, syenite

Associated minerals

Analcime, Heulandite, Calcite, Benitoite

Geography

Czech Republic, India, USA

Classification

Rarity

uncommon

Gem quality

No

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