Quartz Vein in Sedimentary Rock

Physical Properties

Hardness: 7 (quartz) / 3-4 (matrix). Color: white to creamy tan. Luster: vitreous (crystals) to dull (matrix). Structure: crystalline quartz seam within a fine-grained sedimentary bed. Specific gravity: approx. 2.65.

Formation & Geological History

Formed through hydrothermal precipitation where silica-rich fluids filled fractures or voids in sedimentary host rock. This usually occurs during late-stage burial or tectonic activity.

Uses & Applications

Primarily of interest to amateur collectors and geologists as a representative specimen of mineral mineralization within host rocks.

Geological Facts

Quartz is the most abundant mineral in the Earth's crust after feldspar. These 'seams' are common and show how fluids move through the earth's subsurface over millions of years.

Field Identification & Locations

Identify by checking for a crystalline 'sandwich' layer. If the crystal part scratches glass but the outer rock doesn't, it is a quartz vein in a softer matrix like limestone or weathered chert.

Identified on: 4/13/2026

Mode: Standard