Rocks & Minerals Encyclopedia

Browse by type

• mineralNaturally occurring crystalline solids5834 entries
• fossilPetrified, agatized, and mineralized remains151 entries
• gemstoneCut and collectible gem materials96 entries
• sedimentaryLayered rocks formed by deposition45 entries
• igneousBorn from molten rock43 entries
• metamorphicTransformed by heat and pressure32 entries

Browse by color

What color is the rock you're holding? Start there.

• white2304 rocks
• colorless1796 rocks
• yellow1744 rocks
• brown1338 rocks
• black1070 rocks
• gray862 rocks
• pale yellow464 rocks
• green383 rocks
• pink345 rocks
• red336 rocks
• blue318 rocks
• reddish-brown309 rocks
• orange267 rocks
• dark brown250 rocks
• yellowish220 rocks
• yellowish-brown219 rocks

Start here

Two entry points for new rockhounds and trip planners.

• Beginner-friendly rocksEasy to find, identify, and handle→
• Rocks by U.S. stateGeology changes at the state line→

Browse by Mohs hardness

Test your specimen against a known reference, then narrow it down.

• 1260 rocks
• 21834 rocks
• 32721 rocks
• 41910 rocks
• 51444 rocks
• 61497 rocks
• 7778 rocks
• 8187 rocks
• 950 rocks

Popular collections

• common rocks & minerals780 entries→
• uncommon rocks & minerals521 entries→
• rare rocks & minerals4900 entries→
• Fluorescent minerals377 that glow under UV→

Most loved by rockhounders

Iconic finds and collector favorites from around the world.

• 
  Lake Superior Agatecommon

  mineral · Mohs 6.5-7red, orange, yellow
• 
  Herkimer Diamondcommon

  mineral · Mohs 7colorless, smoky
• 
  Wood Opalcommon

  fossil · Mohs 5.5-6.5brown, tan, gray
• 
  Oregon Sunstoneuncommon

  gemstone · Mohs 6-6.5yellow, red, green
• 
  Fairburn Agaterare

  mineral · Mohs 6.5-7red, yellow, brown
• 
  Turquoisecommon

  mineral · Mohs 5-6blue, blue-green, green
• 
  Amethystcommon

  gemstone · Mohs 7purple, violet, lavender
• 
  Smoky Quartzcommon

  mineral · Mohs 7brown, gray, black
• 
  Geodecommon

  sedimentary · Mohs 7white, gray, brown
• 
  Montana Moss Agatecommon

  mineral · Mohs 6.5-7clear, white, gray
• 
  Trilobite Fossilscommon

  fossil · Mohs 3-5black, brown, gray