metamorphic

Weathered quartz-bearing metamorphic rock, likely mica schist or gneiss

Quartz–feldspar–mica assemblage; exact mineral identification requires testing

AI-generated identification · may be incorrect

Gray-brown, coarse-grained, sparkly appearance from mica, with pale quartz/feldspar and rusty iron-oxide staining. Likely Mohs hardness 2–7 overall; mica shows platy cleavage, while quartz is vitreous and hard.

Identified September 6, 2026More metamorphic →

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At a glance

Common name: Weathered quartz-bearing metamorphic rock, likely mica schist or gneiss
Scientific name: Quartz–feldspar–mica assemblage; exact mineral identification requires testing
Category: metamorphic
Identified: September 6, 2026
Method: Standard

AI Estimated Value

About $2–$15 as an ordinary hand specimen; attractive labeled specimens may sell for roughly $20–$50.

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

Probably formed when sedimentary or igneous rock was buried, heated, and compressed during regional metamorphism, commonly during Precambrian–Paleozoic mountain building. Surface oxidation and weathering produced the brown staining.

Uses & applications

Typically used as a teaching or collecting specimen; massive schist or gneiss may be used locally as dimension stone, aggregate, or landscaping rock, but this piece has little commercial value.

Geological facts

The reflective flakes are most likely muscovite or biotite mica. A streak test, hardness testing, and examination of foliation would distinguish schist from gneiss and identify the dominant minerals.

Field identification & locations

Look for foliation or aligned mica layers, visible quartz/feldspar grains, and a nonmetallic sparkle; it should not fizz with dilute hydrochloric acid unless carbonate minerals are present. Common in ancient metamorphic terrains worldwide, including the Appalachians, Canadian Shield, and Scandinavia.