NASA's Perseverance rover has captured images of a highly unusual rock - one that seems highly ... which NASA says is the most powerful type of volcanic blast there is. Images of ‘Araneiforms ...

Evidence for the use of rock crystal - a rare type of perfectly transparent quartz which forms in large hexagonal gems - has occasionally been found at prehistoric sites in the British Isles, but ...

A compound is a substance that contains two or more elements close elementA pure substance that is made from only one type of atom ... For example, the rock malachite is mostly made of the ...