What's That Rock?Quartz
Also called: rock crystal, clear quartz
One of the most common minerals in the Earth's crust. Clear or white, glassy, and hard enough to scratch glass.
How to identify Quartz
- Scratches glass and a steel knife blade
- Breaks with smooth curved surfaces (conchoidal fracture), not along flat planes
- Six-sided crystals with pointed tips when it grew with room to spare
Often confused with
Real or fake?
- Glass often shows round bubbles or swirl marks inside; quartz shows irregular cracks and wispy inclusions
- Quartz is hard enough to scratch glass; most glass will not scratch quartz
Is Quartz valuable?
Common and inexpensive. Clear, well-formed crystals and clusters cost more than rough pieces.
Typical retail prices
Tumbled stone$1–4each
Rough$5–25per pound
Collector specimen$10–200each
Typical retail ranges in US dollars, compiled from public dealer and marketplace listings in October 2026. Real prices vary widely with quality, size and origin. This is general information, not an appraisal.
What changes the price
- Crystal quality: clear, sharp, undamaged points and clusters cost more than milky, chipped pieces
- Size: large clean crystals and big clusters can cost hundreds
- Special forms: phantoms, Herkimer 'diamonds', scepters and water-clear Brazilian crystals cost more
- Most quartz is common and cheap, tumbled and rough pieces cost a few dollars
Uses
- Jewelry and decorative stones
- Glassmaking and electronics (synthetic quartz keeps time in watches)
Care
Safe to wash with water. Bright sun can fade some colored varieties.
Identifying a stone from a description or a photo is an estimate. Many stones look alike. Ask an expert or a gem lab before you buy, sell or rely on an identification.
Updated October 2026