Agate
brownwhitegrayblue · Chalcedony family
| Also known as | Chalcedony (Chalcedony family) |
|---|---|
| Colour | Brown, White, Gray, Blue |
| Mohs hardness | 6.5–7 |
| Lustre | Waxy, vitreous when polished |
| Streak | White |
| Crystal system | Trigonal (quartz) or monoclinic (moganite) |
| Transparency | Transparent to opaque (usually translucent) |
| Cleavage | None |
| Fracture | Conchoidal |
| Chemical formula | SiO 2 (silicon dioxide) |
| Specific gravity | 2.60–2.64 |
What is Agate?
Agate is a banded variety of fibrous chalcedony. Agate stones are characterized by alternating bands of different colored chalcedony and often contain some visible quartz crystals. They are common in nature and can be found globally in a large number of different varieties. Most agates are concentrically banded, while some have bands that form parallel lines. Certain varieties of chalcedony without bands are commonly called agate, but these are not true agates. Moreover, not every banded chalcedony is an agate.
How to identify Agate
- Lustre: Waxy, vitreous when polished.
- Hardness: Mohs 6.5–7 — about as hard as a steel knife.
- Streak: White.
- Habit: Trigonal (quartz) or monoclinic (moganite) crystal system.
Agate value
Based on 100 recent eBay sold listings, a polished / carved Agate typically sells for $6–$8 (about $0.04–$0.12 per gram for raw material). After eBay fees a seller nets roughly $6 on a median piece.
| Recently sold | Weight | Sold | Date |
|---|---|---|---|
| 202G Natural Red Orange Sardonyx Agate Sphere Quarzt Crystal Ball Reiki Healing | 202 g | $7 | 2026-06-22 |
| 76G Natural Druzy Blue Lace Chalcedony Agate Tower Quartz Crystal Reiki Healing | 76 g | $7 | 2026-06-22 |
| 3.82LB Natural Amethyst with Banded Agate Carved Nine-tailed Fox Crystal Healing | 1733 g | $7 | 2026-06-22 |
| 242G Natural Red Orange Sardonyx Agate Sphere Quarzt Crystal Ball Reiki Healing | 242 g | $7 | 2026-06-22 |
| 380G Natural Aquatic Agate Geode Obelisk Crystal Wand Point Energy Healing Reiki | 380 g | $7 | 2026-06-22 |
| 360g Natural Volcanic agate Crystal Ball Sphere Polished Mineral Healing Reiki | 360 g | $8 | 2026-06-22 |
Typical recently-sold prices, 2026-06. Condition, size and quality vary widely, so this is an estimate, not an appraisal. See current sold listings on eBay ↗. Full value guide · how we work this out.
