Crystals are forming out of shallow water that has flooded the bottom of Death Valley. It is so hot and dry that the water evaporates and mineral crystals are left behind!
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Courtesy of Martin Miller, University of Oregon

Some Sedimentary Rocks Are Made of Crystals!

Some sedimentary rocks are made of mineral crystals that come from oceans, lakes, and groundwater. Water can have all the ingredients that are needed to make mineral crystals!

How does water hold the ingredients to make minerals? See for yourself by putting a spoonful of salt into a glass of water. The salt will dissolve into the water. You canít see it anymore, but it is still there and if you take a sip of the water you will know it! Seawater tastes salty because there are salty minerals such as halite dissolved in it.

Sometimes water becomes so full of dissolved minerals that they will not all fit. When some of the water evaporates away, there is less room for the dissolved minerals. If they do not all fit, crystals of halite, gypsum, and calcite may form.

Last modified August 25, 2003 by Lisa Gardiner.

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