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
• Specific gravity: 2.2
  

Average size: .5 inches