CV2013 Rock Set

Granite

Coarse-grained intrusive igneous rock rich in quartz, feldspar, and mica. Light-colored and felsic.

Basalt

Fine-grained extrusive igneous rock rich in pyroxene and plagioclase. Dark-colored and mafic.

Gabbro

Coarse-grained intrusive igneous rock chemically equivalent to basalt. Dark-colored and mafic.

Rhyolite

Fine-grained extrusive igneous rock chemically equivalent to granite. Light-colored and felsic.

Andesite

Intermediate extrusive igneous rock with plagioclase, amphibole, and pyroxene. Often gray.

Sandstone

Sedimentary rock formed from compacted sand-sized particles. Often shows bedding.

Shale

Fine-grained sedimentary rock formed from clay and silt. Splits easily into thin layers.

Conglomerate

Sedimentary rock made of rounded gravel-sized clasts cemented together.

Breccia

Sedimentary rock similar to conglomerate but with angular clasts.

Limestone

Sedimentary rock composed mainly of calcite. Reacts strongly with dilute acid.

Dolostone

Sedimentary rock composed mainly of dolomite. Reacts weakly with acid unless powdered.

Chert

Hard, fine-grained sedimentary rock made of microcrystalline quartz. Breaks with conchoidal fracture.

Quartzite

Metamorphic rock formed from sandstone. Very hard, quartz grains fused together.

Marble

Metamorphic rock formed from limestone or dolostone. Composed of calcite or dolomite, reacts with acid.

Schist

Metamorphic rock with pronounced foliation and visible mica minerals.

Gneiss

Metamorphic rock with banded foliation caused by mineral segregation.

Slate

Low-grade metamorphic rock formed from shale. Breaks into thin sheets.

Granite vs Rhyolite

Both felsic igneous rocks. Granite is coarse-grained intrusive, rhyolite is fine-grained extrusive.

Basalt vs Gabbro

Both mafic igneous rocks. Basalt is fine-grained extrusive, gabbro is coarse-grained intrusive.

Granite vs Basalt

Granite is felsic light-colored intrusive, basalt is mafic dark-colored extrusive.

Shale vs Slate

Shale is sedimentary with clay minerals, slate is metamorphosed shale with harder, foliated texture.

Sandstone vs Quartzite

Sandstone is sedimentary with loose quartz grains, quartzite is metamorphic with fused quartz grains.

Limestone vs Dolostone

Both carbonate rocks. Limestone = calcite CaCO₃, dolostone = dolomite CaMg(CO₃)₂. Reactivity with acid differs.

Conglomerate vs Breccia

Both clastic sedimentary rocks with large clasts. Conglomerate has rounded clasts, breccia has angular clasts.

Schist vs Gneiss

Both metamorphic and foliated. Schist has platy minerals aligned, gneiss has banded layers from mineral segregation.

Marble vs Quartzite

Both non-foliated metamorphic. Marble = calcite/dolomite, reacts with acid. Quartzite = quartz, very hard, does not fizz.