Rock identification guides
Practical guides for anyone who picks up interesting stones, from first-time finders to weekend collectors.
How to identify rocks: a simple step-by-step guide
Six tests you can do with a nail, a glass bottle and some vinegar.
Common rocks and minerals you're likely to find
The 15 you'll meet most often, and the one detail that gives each away.
Is my rock valuable? How to tell if a rock is worth money
What makes a rock worth something, and how to check before you sell.
Limestone vs marble: how to tell them apart
They're made of the same mineral. Here's how to see the difference.