Rock & Mineral Identification Guides
Free field guides written for collectors, students, and the simply curious — from your first "what rock did I find?" to running streak, luster, and Mohs hardness tests like a geologist.
Identify what you found
How to Identify Rocks
The complete beginner's method for naming any rock: color, hardness, streak, luster, and where a photo ID app fits in.
Rock Identification Guide
Understand the three rock families — igneous, sedimentary, and metamorphic — and the telltale features that separate them.
What Rock Did I Find?
A practical walkthrough for identifying the mystery rock in your hand, from geodes and agates to plain gray quartzite.
Mineral & crystal guides
How to Identify Minerals
Use hardness, streak, cleavage, and luster to name minerals with confidence — plus the modern AI shortcut.
Mineral Identification Guide
A deeper reference on the classic diagnostic tests — streak, luster, and cleavage — and how to read the results.
Mohs Hardness Scale
The 1–10 hardness scale explained, with easy scratch tests using a fingernail, coin, knife, and glass.
How to Identify Crystals
Tell real crystals from glass and fakes, and learn the fastest way to identify any crystal from a photo.
Crystal Identification Guide
Read crystal systems, habits, and colors to identify quartz, amethyst, calcite, and other common crystals.
How to Identify Gemstones
How to tell whether that colorful stone is a genuine gemstone, and which tests separate the real thing from imitations.
Rockhounding in the field
Rockhounding for Beginners
Gear, rules, ethics, and where you can legally collect rocks — everything you need to start the hobby right.
Find Rockhounding Sites Near You
How to find legal collecting spots close to home, from BLM and Forest Service lands to known mineral localities.
Digital Geology Field Guide
How a phone replaces a backpack of reference books: offline maps, mineral databases, and field tools in one app.
Apps & tools
Best Rock Identification App 2026
An honest comparison of today's rock identifier apps — accuracy, features, pricing, and which one to download.
Rockhound: Rock Identifier — put these guides into practice: snap a photo, get an AI identification with a confidence score, and have a real geologist verify it. Free on iOS.
Download FreeSkip the guesswork
Reading is great — but the fastest way to identify a rock is a photo. Download Rockhound free and get an answer in seconds.
Download Rockhound FreeiPhone & iPad · iOS 17.6+ · No account required to start