What's That Rock?Diamond
Pure carbon with a crystal structure that makes it the hardest natural material. Most diamonds are small and used in industry.
How to identify Diamond
- Scratches everything and cannot be scratched by anything natural
- Rough crystals are often rounded octahedra with a greasy shine
- Conducts heat fast: it feels cold and clears fog quickly
Often confused with
- Moissanite
- Cubic zirconia
- White sapphire
- Quartz
- Glass
Real or fake?
- Fogging test: breathe on it. A diamond clears almost at once; imitations stay fogged longer
- Only a gem lab or a proper tester can tell diamond from moissanite and lab-grown diamond
Is Diamond valuable?
Value depends on size, cut, color and clarity. Always use a certified lab report.
Typical retail prices
Gem-quality natural diamonds vary from about $1,500 to far more than $15,000 per carat. Lab-grown diamonds cost a small fraction. Get a certified report.
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
- The 4 Cs: cut, color, clarity and carat weight decide the price; a certified report from a recognized lab (GIA, IGI) is essential
- Natural or lab-grown: lab-grown diamonds are chemically the same and cost a small fraction of natural stones
- Fancy colors: natural pink, blue and red stones are extremely rare and costly, treated colors are cheap
- Rough diamonds are worth far less than cut stones and are very hard to judge by eye
- Look-alikes: moissanite, cubic zirconia and white sapphire are often sold as diamond
Uses
- Jewelry
- Industrial cutting and drilling
Care
Very hard but can chip on a sharp blow along cleavage.
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