Rocks & Minerals
Identify rocks, minerals, gemstones, and fossils with AI.
All articles
Visual Crystal ID: A Specialist’s Field Guide
Use this crystal identifier guide to visually identify minerals, gems, and jewelry. Learn tests, visual cues, habitat info, and app tips with Orvik.
February 20, 2026
Obsidian: The Volcanic Glass Explained
Learn what obsidian what type of rock is, how it forms, visual ID tips, uses, safety, and where to find it. Practical field guidance and comparisons.
February 19, 2026
Diamond and the Hardest Rocks: A Field Guide
Discover what is the hardest rock, how hardness is measured, where diamonds form, and practical field ID tips. Use Orvik to ID rocks in the wild.
February 18, 2026
Granite: Field Guide to a Classic Rock
Identify granite with confidence: learn what it's made of, why granite is what type of rock, visual ID tips, comparisons, distribution, and safety notes.
February 7, 2026
Field Guide to Identifying Fossils
A smart fossil identifier for photos: learn visual cues, habitat, bone vs shell comparisons, and safe collecting tips for beach and field finds.
January 29, 2026
Inside the Geode: A Field Guide to Crystal Pockets
Learn what is a geode—how they form, how to identify and open them safely, where to find them, and how to tell agates and nodules apart.
January 18, 2026
Identify Crystals with Confidence
Find the best crystal identification app, plus expert visual ID tips and safety notes. Use Orvik or free crystal identifier apps to identify crystals fast.
January 18, 2026
Inside Igneous Rock: Formation, Types & Field ID
Learn what are igneous rock: formation, types, visual ID tips, and where to find them. Use Orvik to identify samples in the field with confidence.
January 17, 2026
Basalt in the Field: A Practical Guide
Learn what is basalt — a dark, fine-grained mafic igneous rock. Identify basalt in the field with clear visual cues, formation, uses, and safety tips.
January 13, 2026
Sandstone: How to Identify and Where It Forms
Learn what are sandstone, how they form, how to identify them in the field, and how to tell them from quartzite or shale — practical tips and safety steps.
January 10, 2026
What Chalk Is: Origins, Composition, and ID Tips
Learn chalk is made of what: composition, formation, field ID tips, and comparisons with chert, shale, diatomite and oil shale—plus safety and uses.
January 3, 2026
Identifying Limestone: The Basics
If you ask "limestone is what type of rock" this guide shows how to ID it—composition (CaCO3), HCl test, textures, habitats, safety, and comparisons.
January 2, 2026