Identify Rocks

Granite

Granite is a hard igneous plutonic rock of quartz, feldspar and mica.

💡 Did you know? You recognise it by its speckled light and dark grains.

Basalt

Basalt is a dark volcanic rock that often forms hexagonal columns.

💡 Did you know? The ocean floor is mostly made of basalt.

Marble

Marble forms from limestone under heat and pressure; it is usually white.

💡 Did you know? Michelangelo’s „David“ is carved from Carrara marble.

Sandstone

Sandstone consists of cemented sand grains and is often yellowish to reddish.

💡 Did you know? Many castles, churches and whole cities are built of sandstone.

Limestone

Limestone is mostly calcium carbonate and often comes from marine deposits.

💡 Did you know? Dripstone caves form in limestone.

Slate

Slate can be split into thin, flat plates and is used for roofing.

💡 Did you know? In the past, pupils wrote on slate tablets at school.

Obsidian

Obsidian is glassy solidified lava, usually deep black with sharp edges.

💡 Did you know? Even Stone Age people made razor-sharp blades from it.

Pumice

Pumice is so porous and light that it floats on water.

💡 Did you know? It is used to rub away hard skin.

Gneiss

Gneiss is a metamorphic rock with a typical light-and-dark banding.

💡 Did you know? It forms deep in the Earth under great heat and pressure.

Tuff

Tuff forms from consolidated volcanic ash and is soft and easy to work.

💡 Did you know? Many ancient buildings are made of tuff.

Conglomerate

A conglomerate consists of cemented, rounded pebbles.

💡 Did you know? It looks like fossilised concrete.

Quartzite

Quartzite is a very hard rock formed from sandstone under pressure.

💡 Did you know? It consists almost entirely of quartz.