Rock identification guides

Most finds can be narrowed down with a few simple tests: hardness, streak, luster, weight and a magnet. These guides show how, and which results point to which rock.

• Rock identifierAnswer a few questions about your rock
• How to identify rocksThe basic tests and the three rock families
• Is it a geode?Signs to check before you crack it
• How to identify agatesLight, banding and luster
• Agate vs jasperTwo kinds of chalcedony, one easy test
• How to identify a meteoriteAnd how to rule out look-alikes