The Rockhound dictionary
1,043 minerals, gem varieties, rocks, fossils, meteorites, organic gems, and lapidary materials, with how to tell them apart. Shared by everyone who uses Rockhound: pick one of these names when you add a specimen, and its properties fill themselves in.
13 entries fit.
| Name | Hardness | Streak | Lustre | Colours |
|---|---|---|---|---|
| Abalone shell Organic gem |
3–4 | pearly | blue, green, purple, pink, iridescent | |
| Amber ⚠️ Organic gem |
2–2.5 | white | resinous | yellow, honey, orange, brown, red, rarely blue or green |
| Ammolite ⚠️ Organic gem |
3.5–4.5 | vitreous, pearly | red, orange, green, gold, blue, violet, iridescent | |
| Baltic amber ⚠️ Organic gem |
2–2.5 | white | resinous | yellow, honey, cognac, cloudy white |
| Black coral Organic gem |
2.5–4 | waxy, resinous | black, dark brown | |
| Copal ⚠️ Organic gem |
1.5–2.5 | white | resinous | pale yellow, yellow, orange |
| Coral Organic gem |
3–4 | vitreous, waxy | red, pink, orange, white | |
| Dominican amber ⚠️ Organic gem |
2–2.5 | white | resinous | yellow, orange, red, blue |
| Ivory ⚠️ Organic gem |
2–3 | greasy, dull | white, cream, yellowish, browning with age | |
| Jet Organic gem |
2.5–4 | dark brown | waxy, resinous | black, dark brown |
| Mammoth ivory ⚠️ Organic gem |
2–3 | greasy, dull | cream, tan, brown; outer bark brown or blue | |
| Mother of pearl Organic gem |
3–4 | pearly | white, cream, silver, pink, grey, iridescent | |
| Pearl ⚠️ Organic gem |
2.5–4.5 | pearly | white, cream, pink, silver, gold, grey, black |
The dictionary's figures are typical ones, and specimens vary. ⚠️ marks entries with a caution (toxic, radioactive, or easily damaged): open one to see what to do.