mineral

Quartz with Feldspar and Matrix

Silicon Dioxide (SiO2) with Potassium/Plagioclase Feldspar

Hardness: 7 on the Mohs scale for quartz (6-6.5 for feldspar). Color: White, clear, and pale greenish-tan with earthy brown weathered patches. Luster: Vitreous to greasy on fresh crystal faces, dull on weathered surfaces. Crystal structure: Trigonal (quartz) and triclinic/monoclinic (feldspar).…

Hardness: 7 on the Mohs scale for quartz (6-6

Identified August 1, 2026More mineral →

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Physical properties

Formation & geological history

Formed typically in pegmatites, hydrothermal veins, or granitic intrusive environments through the cooling and crystallization of silica-rich magmas and hydrothermal fluids over millions of years.

Uses & applications

Used in electronics, glassware, precision instruments, countertops, and as mineral specimens for geological collections.

Geological facts

Quartz is one of the most abundant minerals in the Earth's continental crust. Pegmatite specimens often host large, well-formed crystals of quartz alongside feldspar and micas.

Field identification & locations

Commonly found in pegmatite dikes, granite outcroppings, and alluvial gravels worldwide. The provided location (near central Montana) is well-known for its rich mountain ranges containing granite intrusions, pegmatites, and quartz veins, making this a geologically plausible specimen for the area.

Other mineral specimens

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Soil with Mineral Detritus and Quartz Fragments

Regolith / Silicate Mineral Aggregate

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Limonite / Goethite (Iron Ore Mineral nodule)

FeO(OH)·nH2O / FeO(OH)

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Schist

Metamorphic

Septarian Pebble

Septarian nodule / Concretion

sedimentary

Potassium Feldspar (Orthoclase)

Orthoclase (KAlSi3O8)

mineral