Texas Rocks and Minerals

Earth's outer crust

Geologists

Time and rock units

Geologic map

What are rocks and minerals?

Chemical elements

Minerals

Rocks

Igneous rocks

Extrusive or volcanic igneous rocks

Intrusive igneous rocks

Sedimentary rocks

Soils

Sedimentary rock materials in broken fragments

Sedimentary rock materials in solution

Cementing materials and chemical sediments

Sedimentary rocks formed by plants and animals

Metamorphic rocks

Static metamorphism

Contact metamorphism

Dynamic metamorphism

Occurrence and properties of minerals

How minerals occur

Crystalline minerals

Crystals

Imperfect crystals

Amorphous minerals

Some distinguishing properties of minerals

Color

Luster

Transmission of light

Hardness

Streak or powder

Cleavage

Parting

Fracture

Specific gravity

Effervescence in acid

Some special occurrences of minerals

Cave deposits

Concretions

Geodes

Petrified wood

Collecting rocks and minerals

Rock and mineral identification charts

How to use the mineral identification charts

Key to mineral identification charts

Mineral identification charts

How to use the rock identification charts

Rock identification charts

Descriptions of some Texas rocks and minerals

Anhydrite

Asbestos

Barite

Basalt

Calcite

Cassiterite

Celestite

Cinnabar

Clay

Copper minerals (chalcocite, chalcopyrite, malachite, azurite)

Dolomite

Feldspar

Fluorite

Galena

Garnet

Gneiss

Gold

Granite

Graphite

Gypsum

Halite

Hematite

Limestone

Limonite

Llanite

Magnetite

Manganese minerals (braunite, hollandite, pyrolusite)

Marble

Mica

Obsidian and vitrophyre

Opal

Pegmatite

Pyrite

Quartz

Quartzite

Rhyolite

Sand and sandstone

Schist

Serpentine

Shale

Silver minerals (argentite, cerargyrite, native silver)

Sulfur

Talc and soapstone

Topaz

Tourmaline

Uranium minerals (carnotite, uranophane, pitchblende)

Volcanic ash (pumicite)

Composition, hardness, and specific gravity of some Texas minerals

Books about rocks and minerals

Nontechnical books for beginners

Textbooks and other reference books

Selected references on Texas rocks and minerals