mineral

Astrophyllite in matrix

(K,Na)3(Fe,Mn)7Ti2Si8O24(O,OH)7

AI-generated identification · may be incorrect

Hardness: 3-4. Color: bronze to golden-yellow blades in white or light-colored matrix (often quartz, feldspar, and aegirine). Luster: Sub-metallic, pearly, or greasy. Crystal structure: Triclinic. Cleavage: Perfect on {001}. Specific gravity: 3.3-3.4.

Hardness: 3-4
Luster: Sub-metallic, pearly, or greasy

Identified August 29, 2026More mineral →

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Physical properties

Formation & geological history

Forms in unusual igneous rocks, specifically in nepheline syenites and alkaline granites. Often found associated with other rare minerals. Formed during the cooling and crystallization of these specific magma types.

Uses & applications

Primarily valued by mineral collectors for its striking, star-like or bladed radiating formations. Not typically used in jewelry due to its softness and perfect cleavage, though sometimes cut into cabochons for collectors.

Geological facts

The name comes from the Greek words 'astron' meaning star and 'phyllon' meaning leaf, referring to its radiating, micaceous structure. It was first discovered in 1854 on Laven Island, Norway.

Field identification & locations

Identified by its distinctive golden-brown to bronze radiating blades or starburst patterns against a lighter matrix. Found notably in Russia (Kola Peninsula), Norway, Canada (Mont Saint-Hilaire), and the USA (Colorado). Collect carefully as the crystals are brittle.