Igneous Rocks and Minerals - Rock Cards

Rocks come in various types, each with distinctive characteristics and formation processes. Conglomerate is a coarse-grained sedimentary rock with rounded grains, while sandstone is another sedimentary variety, primarily composed of sand-sized particles and often found in layered formations. Shale stands out as a sedimentary rock with such fine grains that they are not easily discernible upon inspection. In contrast, basalt is an igneous rock, known for its richness in magnesium and iron, distinguishing it from sedimentary types. Coal, a sedimentary rock, is notably formed from plant matter that has converted to carbon and is discovered in underground seams, making it one of humanity's most valued resources.

Other notable sedimentary rocks include chalk, a soft and porous rock made of calcium carbonate, highly vulnerable to chemical weathering, and mudstone, which originates from clay and mud. Limestone shares similarities with chalk, being composed of calcium carbonate as well. Transitioning to metamorphic rocks, marble is a transformed version of limestone, traditionally cherished for sculpture, while slate derives from shale or silt, and schist features distinct bands of colored rock. Gneiss, a common metamorphic rock, and hornfels, an unusual banded rock formed by the intense heat from igneous rock, are also part of this diverse category. Additionally, the rock collection includes novaculite, a dense metamorphic rock from the US and Japan, phyllite, primarily composed of mica, migmatite, a blend of metamorphic and igneous rock, and diorite, an igneous rock dominated by feldspar. Lastly, igneous rocks such as gabbro, granite, and hornblende are noted for their hardness and deep underground formation, while obsidian is recognized as a black volcanic glass, pumice as a low-density rock with gas bubbles, tuff as a rock formed from volcanic ash, and rhyolite as a high silica volcanic rock.