rocks & minerals

Rocks

Igneous

  Granite--quartz, feldspar, & hornblende
  Diorite
  Basalt (columnar)
  Pumice
     Magma--below ground
     Lava--above ground

Diorite

"Diorite is a grey to dark grey intermediate intrusive igneous rock composed principally of plagioclase feldspar (typicallyandesine), biotite, hornblende, and/orpyroxene. It may contain small amounts of quartz, microcline andolivine."

"Diorite is a relatively rare rock; source localities include Leicestershire; UK (one name for microdiorite - Markfieldite - exists due to the rock being found in the village of Markfield),Sondrio, Italy; Thuringia and Saxony inGermany; Finland; Romania; Northeastern Turkey; central Sweden; Scotland; the Darrans range of New Zealand; the Andes Mountains; the Isle of Guernsey; Basin and Range province; Minnesota in the USA, and Idahet in Egypt.

An orbicular variety found in Corsica is called corsite."

Metamorphic

  igneous rock under pressure; crystal structure transformed
  Gneiss

Gneiss

"Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks."

Sedimentary

  sediment turned into rock
     Shale
     Slate
     Sandstone
     Siltstone
     Shellstone: coquina
     Limestone
     Kaolinite

Shale

"Shale is a fine-grained, classic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite."
Shale is often found in slow-moving water, lakes, lagoons, river deltas, floodplains, and offshore from beach sands.

Minerals

Quartz
Feldspar
Hornblende
    pyrite, halite, calcite, mica

Quartz

"Quartz is an abundant mineral in the Earth's continental crust. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz, several of which are semi-preciousgemstones. Throughout the world, varieties of quartz have been, since antiquity, the most commonly used minerals in the making of jewelry and hardstone carvings."