mineral

Tumbled orange-brown feldspar, likely sunstone or aventurine feldspar

Potassium feldspar, commonly orthoclase or oligoclase; approximate composition KAlSi₃O₈–NaAlSi₃O₈

AI-generated identification · may be incorrect

Hardness 6–6.5 Mohs; orange-brown, translucent to opaque, with a vitreous to resinous polish and whitish internal cleavage or inclusions. Feldspar is tectosilicate with two good cleavage directions, though these are obscured by tumbling.

Identified August 28, 2026More mineral →

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At a glance

Common name: Tumbled orange-brown feldspar, likely sunstone or aventurine feldspar
Scientific name: Potassium feldspar, commonly orthoclase or oligoclase; approximate composition KAlSi₃O₈–NaAlSi₃O₈
Category: mineral
Identified: August 28, 2026
Method: Standard

AI Estimated Value

Approximately $2–$15 for a common tumbled piece; $20–$100+ if it displays strong natural aventurescence or is verified as quality sunstone.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Formed by crystallization from silica-rich igneous melts, commonly in granitic or pegmatitic rocks; individual grains may be Precambrian to younger. Orange color can result from iron-bearing inclusions, while true sunstone may show aventurescence from reflective platelets.

Uses & applications

Used primarily as a decorative, lapidary, and jewelry stone; feldspar is also important industrially in glass and ceramic manufacture. This small tumbled piece has modest specimen value.

Geological facts

The appearance is consistent with orange feldspar but cannot confirm visible aventurescence from the photograph alone. It may also be sold commercially as orange aventurine feldspar or Oregon sunstone rough/tumbles.

Field identification & locations

Identify by its salmon-orange color, moderate hardness, feldspar cleavage, and occasional glittering schiller; it should scratch glass but not quartz. Common sources include Oregon, India, Tanzania, Madagascar, and granitic pegmatites worldwide.