How to Identify Sea Rocks

Look for obsidian rocks. Obsidian is an igneous rock that is formed by quick-cooling magma. The surface is black and shiny and glassy. This dark beauty makes obsidian a popular choice for making jewelry.

Check for colorful sandstone rocks. Sandstone is a very common sedimentary rock. It’s comes in many different colors, because it’s made up of compacted silt and other bits that have settled on the floor of a body of water. Sandstone includes quartz and feldspar and pieces of other kinds of rocks that have been cemented together and remained for thousands of years.

Watch for the beautiful gneiss sea rocks. Gneiss is a metamorphic rock, meaning that heating and other physical processes have changed a couple different types of rock to make a new one. Because of the process that makes it, gneiss has bands and is quite beautiful. Look for rocks with bands of colors. No two gneiss pieces can be exactly the same.

Identify crystal-looking basalt rocks. Basalt is a gray-to-black igneous rock that is commonly found on the ocean floor. It’s also commonly found on the moon. The rock features large crystals and looks quite rough. If the rock cools slowly enough, the crystal structure will transfer from the micro to the macro and form large formations in which the rocks have split into what looks like a large pentagonal brick road.

Learn about the muddy shale. Shale is a sedimentary rock with very fine grains. It’s usually the color of mud, since that is what it’s made from. There are also commonly small striations that let you see the layers it took to put the shale together over long periods of geological time.