Rocks: Pictures of Igneous, Metamorphic and Sedimentary Rocks
Photographs and information for a large collection of igneous, metamorphic and sedimentary rocks. Geology.com.
Sedimentary Rocks | Pictures, Characteristics, Textures, Types
There are three basic types of sedimentary rocks. Clastic sedimentary rocks form from the accumulation and lithification of mechanical weathering debris. Examples include: breccia, conglomerate, sandstone, siltstone, and shale. Chemical sedimentary rocks form when dissolved materials preciptate
Igneous Rocks | Pictures of Intrusive and Extrusive Rock Types
Extrusive igneous rocks erupt onto the surface, where they cool quickly to form small crystals. Some cool so quickly that they form an amorphous glass. These rocks include: andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff. Pictures and brief descriptions of some common igneous rock types are shown on this page.
Mineral Properties, Photos, Uses and Descriptions - Geology.com
Photos and information about 80 common rock-forming, ore and gemstone minerals from around the world.
Granite: Igneous Rock - Pictures, Definition & More - Geology.com
Granite is the most widely known igneous rock. It is an intrusive rock with visible grains of feldspar, quartz, mica, and amphibole minerals. It is durable and widely used in construction and architecture.
Metamorphic Rocks | Pictures of Foliated and Non-Foliated Types
Metamorphic rocks have been modified by heat, pressure, and chemical processes, usually while buried deep below Earth's surface. Exposure to these extreme conditions has altered the mineralogy, texture, and chemical composition of the rocks. There are two basic types of metamorphic rocks.
Gemstones: Facts, photos, and information for over 100 gems.
Articles about gemstones written by a GIA Graduate Gemologist. Each article includes photos and information about the gem's physical properties and geologic origin.
Types of Meteorites: Iron, Stone, Stony-Iron, Lunar, Martian
Rocks: Galleries of igneous, sedimentary and metamorphic rock photos with descriptions.
Basalt: Igneous Rock - Pictures, Definition, Uses & More
Basalt is a dark-colored, fine-grained, igneous rock composed mainly of plagioclase and pyroxene minerals. It most commonly forms as an extrusive rock, such as a lava flow, but can also form in small intrusive bodies, such as an igneous dike or a thin sill. It …
Obsidian: Igneous Rock - Pictures, Uses, Properties - Geology.com
Obsidian is an igneous rock that forms when molten rock material cools so rapidly that atoms are unable to arrange themselves into a crystalline structure. It is an amorphous material known as a "mineraloid." The result is a volcanic glass with a smooth uniform texture that breaks with a conchoidal fracture (see photo).