Physics

Pyroxene Definition Pyroxene is any of a series of dark silicate minerals having the general chemical formula ABSi 2 O 6, where A is either…

Olivine Definition Olivine is a common mineral in the igneous rocks, such as basalt and gabbro that make up most of the Earth’s crust beneath…

Peridotite Definition Peridotite is a coarse-grained igneous rock that consists mainly of olivine and pyroxene. It is believed to be one of the main constituent…

Kimberlite Definition Kimberlite is a type of peridotite consisting of a fine-grained matrix of calcite and olivine and containing phenocrysts of olivine, garnet, and sometimes…

Diamond Definition Diamond is a form of pure carbon that occurs naturally as a clear, cubic crystal and is the hardest of all known minerals.…

Graphite Definition Graphite is a naturally occurring, steel-gray to black, crystalline form of carbon. It is the most stable form of carbon under standard conditions.…

Helium Definition Helium is a very lightweight, colorless, odorless element in the noble gas group. It is used as a component of artificial atmospheres and…

About Carbon Definition Carbon is a naturally abundant, nonmetallic element that occurs in all organic compounds and can be found in all known forms of…

About Neutron Definition Neutron is an electrically neutral subatomic particle in the baryon family, having a mass of 1.674 × 10-24 grams (1,838 times that…

About Proton Definition Proton is a stable subatomic particle in the baryon family having a mass of 1.672 × 10-24 grams (1,836 times that of…

About Hydrogen Definition Hydrogen is the lightest and most abundant element in the universe, normally consisting of one proton and one electron. It is a…

About Hydrocarbon Definition Hydrocarbon is a class of organic chemical compounds composed only of the elements carbon (C) and hydrogen (H). Hydrocarbons from which one…