Rocks and Minerals

There are three main types of rock groups that rocks and minerals fit into (igneous, metamorphic and sedimentary). The activity below is introducing 5 different rocks from first, igneous then metamorphic, then sedimentary.

Igneous Rocks

How are igneous rocks formed?

An igneous rock is formed through the cooling and solidification of magma or lava.

Describe the minerals in the gallery below.

Felsite: Felsite is a fine-grained, volcanic rock of light colour and is composed mainly of feldspar and quartz. It may also contain phenocrysts. Felsite is typically of volcanic origin and is often found in association with acidic rocks as obsidian or rhyolite.

Basalt: 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.

Granite: Granite is a light-colored igneous rock with grains large enough to be visible with the unaided eye. It forms from the slow crystallization of magma below Earth’s surface.

Rhyolite: Rhyolite is a fine grained, volcanic rock, in composition equal to the plutonic equivalent granite. Rhyolite is formed from silica-rich magma and contains often glassy or microcrystalline aggregates.

Obsidian: 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.

Metamorphic Rocks

How are metamorphic rocks formed?

Metamorphic rocks are rocks that were once one formed of rock but has changed to another under the influence of heat, pressure, or some other agent without passing through a liquid phase.

Describe the minerals in the gallery below.

Quartzite: Quartzite is a rock composed of firmly cemented quartz grains. It results from recrystallization of pure quartz sandstone by metamorphosis (so called metaquartzites). Often quartzites are white or light colored but can also be colored more intensively.

Gneiss: Gneiss is foliated metamorphic rock that has a banded appearance and is made up of granular mineral grains. It typically contains abundant quartz or feldspar minerals.

Marble: Marble is a metamorphic rock that forms when limestone is subjected to the heat and pressure of metamorphism. It is composed primarily of the mineral calcite and usually contains other minerals such as: clay minerals, micas, quartz, pyrite, iron oxides and graphite.

Slate: Slate is a fine-grained, foliated metamorphic rock that is created by the alteration of shale or mudstone by low-grade regional metamorphism. It is popular for a wide variety of uses such as roofing, flooring and flagging because of its durability and attractive appearance.

Greenstone: Greenstone is a tough, dark altered basaltic rock that once was solid deep-sea lava.

Sedimentary Rocks

How are sedimentary rocks formed?

Sedimentary rocks are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water.

Describe the minerals in the gallery below.

Shale: Shale is a fine-grained sedimentary rock that forms from the compaction of silt and clay-size mineral particles that we commonly call "mud". This composition places shale in a category of sedimentary rocks known as "mudstones".

Limestone: Limestone is a sedimentary rock composed primarily of calcium carbonate in the form of the mineral calcite. It most commonly forms in clear, warm, shallow marine waters.

Coal: Coal is a combustible, sedimentary, organic rock, which is composed mainly of carbon, hydrogen and oxygen. It is formed from vegetation, which has been consolidated between other rock strata and altered by the combined effects of pressure and heat over millions of years to form coal seams.

Rock Salt: Rock salt is a chemical sedimentary rock that forms from the evaporation of ocean or saline lake waters. It is also known by the mineral name "halite". It is rarely found at Earth's surface, except in areas of very arid climate.

Travertine: Travertine is a dense, banded sedimentary rock, composed of calcium carbonate. It is formed in cold, temperate surfaces, or ground waters by rapid chemical precipitation of calcium carbonate solutions.


This shows where 6 different landforms and 4 different rocks in the United States are located.

Within this activity, I did a few landforms. These are pictures of the landforms I did (which all landforms are located within the United States).