metamorphic

Blue-gray feldspar-rich rock, likely labradorite-bearing gneiss or anorthosite

Plagioclase feldspar (albite–anorthite series), possibly with labradorite; exact rock identification is uncertain from one photo

AI-generated identification · may be incorrect

Whitish to blue-gray, granular and weakly banded, with dull to vitreous luster. Feldspar hardness is about Mohs 6–6.5; cleavage is good in two directions, and the visible dark patches may be biotite, hornblende, or altered minerals. No clear iridescent labradorescence is visible.

Identified August 30, 2026More metamorphic →

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At a glance

Common name: Blue-gray feldspar-rich rock, likely labradorite-bearing gneiss or anorthosite
Scientific name: Plagioclase feldspar (albite–anorthite series), possibly with labradorite; exact rock identification is uncertain from one photo
Category: metamorphic
Identified: August 30, 2026
Method: Standard

AI Estimated Value

$2–$15 for a common rough piece; $20–$100+ if it shows strong labradorescence, attractive texture, or proven locality.

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

Likely formed by crystallization of a feldspar-rich magma followed by metamorphism or deformation. Such rocks are generally Precambrian to Paleozoic, though the specimen’s age cannot be determined visually.

Uses & applications

Comparable material is used as crushed stone, dimension stone, countertops, and decorative rock; attractive labradorite-rich pieces are used as cabochons and display specimens.

Geological facts

The bluish appearance can result from light scattering in feldspar or alteration, not necessarily from blue quartz. A streak, hardness, and cleavage test would greatly improve identification.

Field identification & locations

Plagioclase-rich metamorphic and igneous rocks are plausible near Spokane, Washington, including rocks related to the Precambrian Belt Supergroup and nearby crystalline terranes. Test a fresh edge with a steel knife: feldspar should resist scratching; inspect for feldspar cleavage and possible flash-like labradorescence.