mineral

Stilbite

Stilbite-Ca (NaCa4Mg[Al9Si27O72]·28H2O)

Hardness: 3.5-4 (Mohs); Color: Pale pink, peach, or white; Luster: Pearly to vitreous; Crystal Structure: Monoclinic; Cleavage: Perfect on {010}; Specific Gravity: 2.1-2.2

Hardness: 3
Color: Pale pink, peach, or white
Luster: Pearly to vitreous

Identified February 6, 2026More mineral →

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Physical properties

Hardness: 3.5-4 (Mohs); Color: Pale pink, peach, or white; Luster: Pearly to vitreous; Crystal Structure: Monoclinic; Cleavage: Perfect on {010}; Specific Gravity: 2.1-2.2

Formation & geological history

Formed in low-grade metamorphic environments or as a secondary mineral in the cavities (vesicles) of volcanic rocks like basalt. These specimens typically formed during the Cenozoic era via hydrothermal activity.

Uses & applications

Primarily sought by mineral collectors for its unique 'bowtie' leaf-like crystal habits and aesthetic colors. Industrially used as a molecular sieve and in water softening (zeolite group).

Geological facts

Stilbite is part of the Zeolite group; its name comes from the Greek word 'stilbein,' meaning 'to shine,' referring to its pearly luster. Large, high-quality peach-colored specimens often come from the Deccan Traps in India.

Field identification & locations

Identify by its distinctive salmon or peach color and 'sheaf-like' or 'bowtie' crystal aggregates. It is commonly found in the basalt quarries of Maharashtra, India, and Iceland. In the field, look for it alongside other zeolites like Heulandite or Apophyllite.