How to Identify Stones Found by Water

Updated March 23, 2017

Rivers, streams, oceans, straits and other bodies of water can be calming to the senses for a quiet walk, but are also exciting to explore and treasure hunt. The treasures are those found in nature, including shells, driftwood and the abundant types of rocks and stones. Many rocks might be metamorphic, sedimentary or volcanic in origin, but most can be accurately named and identified with the help of a book on stone identification, to include agates, jaspers, feldspars and the quartz family.

Contact your local rockhound experts or group. Ask them for suggestions on where to hunt, and if they have a list of rocks common to your area that can be found near water sources. If you live in Hawaii, you're likely to find a lot of volcanic types of rock. If you live in the Pacific Northwest, agates can be found easily. Inland, find an area map for streams and rivers -- even dry beds in deserts yield jasper and other rocks. Also ask for suggestions on the best rock identification book for your locale.

Purchase a book on rock identification or borrow one from the library. Scan the book to get an idea of the regions covered. Ideally, the book will have a lot of clear images with good descriptions on each type of stone. Images of quartz, chert, chalcedony, gypsum, basalt, dolomite, soapstone and slate are fairly standard.

Walk along ocean beaches shortly after sunrise or at sunset to find agates and carnelian along sandstone bluffs. The sun's slant will help light up the stones from behind, so they appear like jewels. On closer inspection, whitish or clear agates may be smooth to the touch or have small-pocketed outer surfaces. They could be banded with lines going in one direction, or forming a 'V' or other shapes. Carnelian is usually reddish orange and very easy to identify. Hold these stones up to the light -- the sun will shine directly through them.

Scour rivers, waterfalls, streams and ponds or lakes for geodes. These look like dull, ordinary rocks, but are more round than most with a surface often covered with rounded indents or nodules. You won't know for sure if the stone has amethyst or other quartz crystals inside unless you visit a lapidary artist or stone mason to cut it, or purchase tools to do the same.

Keep an eye out for obsidian, which looks like black glass due to its high-heat volcanic origins, and jasper, which is usually flat and brownish or cream-coloured with what looks to be pictures or geographic designs on the surface. Olivine is a green glasslike mineral, and the stones are fairly clear. Beaches in some places have tiny stones made of olivine, which wears down over time into a sparkly green "sand." Crystalline rocks include tourmaline, peridot, rose quartz and citrine. These stones are often very clear and colourful, though you might have to rinse them to check. Many will be either a loose crystal form or embedded into the matrix onto which it grew.

Take rocks you find to a local gem or rock shop and ask for identification help. Many people who run such shops are very knowledgeable and will help you sort through your finds.


Carry your rock identification book in your daypack along with water and a snack when rock hunting. A hat and sunscreen are advisable, too, especially for extended hours outdoors on sunny days.


Don't remove stones on privately owned property, unless you have a permit or some other form of permission to do so. Wear protective eye covering and gloves if you are planning to dig around in rocky areas. Watch out for geological hazards such as cliffs that can drop rocks or other potential dangers.

Things You'll Need

  • Good walking shoes
  • Weather-appropriate clothing
  • Area maps
  • Book on rocks
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About the Author

Debra J. Rigas, a professional writing coach, has been a writer and editor since 1975. She is the author of the nonfiction book "Everyone's A Guru" and has edited novels ("The Woman Pope") and worked in arts and sciences as a filmmaker, boat captain, landscaper, counselor, theater administrator and licensed midwife.