mineral

Stilbite

Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O)

Hardness: 3.5-4 on Mohs scale; Color: Peachy-orange to salmon, white, or cream; Luster: Vitreous to pearly (especially on cleavage surfaces); Crystal structure: Monoclinic with characteristic bow-tie or sheaf-like aggregates; Cleavage: Perfect in one direction; Specific Gravity: 2.1-2.2.

Hardness: 3
Color: Peachy-orange to salmon, white, or cream
Luster: Vitreous to pearly (especially on cleavage surfaces)

Identified February 6, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes, typically in the cavities (vesicles) of volcanic basalt. These minerals crystallize from low-temperature hydrothermal fluids during the late-stage cooling of volcanic rocks. Most specimens date from the Mesozoic or Cenozoic eras.

Uses & applications

Primary use is as a collector's mineral and decor. Industrially, as a member of the zeolite group, related minerals are used as molecular sieves for water purification and gas separation, though stilbite itself is mostly of interest to mineralogists.

Geological facts

Stilbite's name comes from the Greek word 'stilbein,' meaning 'to shine,' referring to its pearly luster. It is a member of the zeolite group and is often found growing alongside other minerals like apophyllite, heulandite, and scolecite.

Field identification & locations

Field identification is based on the distinct 'bow-tie' or wheat-sheaf shape of the crystal clusters and the pearly luster on the cleavage faces. Commonly found in the Deccan Traps of India, Iceland, and the basalts of Nova Scotia, Canada. Collectors should handle it with care as it is relatively soft.