Russian Natrolite Tumbles
Russian natrolite is a rare sodium aluminum silicate mineral that's part of the zeolite group. It's usually white or colorless, but can also be reddish, yellowish, gray, brown, green, or bluish
- Hardness: 5–5.5 on the Mohs scale
- Crystal structure: Orthorhombic or pseudo-tetragonal
- Luster: Vitreous, pearly, or silky
- Transparency: Transparent to opaque
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Specific gravity: 2.2
Average size: .5 inches