Guides
Rock and mineral guides
Field-tested answers for rockhounds and the curious: how to identify a rock at home, what hardness and streak tell you, and how to spot fakes.
How to Identify a Rock: A Step-by-Step Guide
Identify a rock or mineral by checking colour, grain, luster, streak, hardness, magnetism and weight, then decide if it is igneous, sedimentary or metamorphic.
Read guide →The Mohs Hardness Scale at Home: How to Do a Scratch Test
Test a mineral's hardness with a fingernail, coin, steel knife and glass. Learn the 10 Mohs minerals and how to do a scratch test without fooling yourself.
Read guide →How to Tell If a Rock Is a Meteorite
Check a suspected meteorite for fusion crust, weight, magnetism and thumbprint marks, rule out meteorwrongs like slag and magnetite, and learn how to verify it.
Read guide →Is My Rock Valuable? What Really Makes a Rock or Mineral Worth Money
What makes a rock or mineral valuable: rarity, crystal quality, size, colour, locality and condition. Which finds can be worth money and how to get a valuation.
Read guide →Real vs Fake Crystals: Common Fakes, Treatments and Simple Checks
Spot dyed howlite sold as turquoise, glass sold as obsidian, heated amethyst sold as citrine, opalite and resin, with simple checks for bubbles, colour and price.
Read guide →Quartz, Calcite or Glass? How to Tell Them Apart
Tell quartz, calcite and glass apart with hardness, cleavage, crystal shape, double refraction, a vinegar fizz test and a look for bubbles. With comparison table.
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