Library
Geology
Rocks, minerals, fossils, meteorites, and the formations that shaped the land you're standing on.
95
entries
5
types
Did you know
The oldest known rocks on Earth are about 4 billion years old — older than the moon's surface.
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Pick a type to see every entry we know about.
Minerals
A naturally occurring inorganic solid with a defined chemical composition.
33
Rocks
A naturally occurring solid aggregate of minerals.
25
Crystals
A solid material with atoms arranged in a highly ordered structure.
16
Fossils
Preserved remains or traces of ancient organisms.
16
Soil Types
Classification of earth material by composition and properties.
5
Featured entries
Hand-picked highlights from the Geology library.
Mineral
Mica (Biotite)
A mineral in the rocks and minerals group.
Crystal
Peridot
Bright green olivine gemstone — August birthstone.
Rock
Granite
Granite is one of the most familiar rocks on Earth — the dominant rock of the continental crust, the material…
Mineral
Garnet
Hard silicate group — typically deep red, used as gem and abrasive.
Rock
Sandstone
Sand grains cemented together — preserves dunes, beaches, and river bars.
Soil Type
Chalky Soil
Alkaline, often pale — overlies chalk or limestone bedrock.
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