Light colored igneous rock is called felsic, it is high in quartz, muscovite mica, and orthoclase feldspar content. Dark colored igneous rock is called mafic, and contains a lesser amount of silica along with olivine, pyroxene, amphibole, biotite mica, and plagioclase feldspa
<span>Light coloured igneous rocks (felsic) tend to have greater silica and aluminum content and a lower iron and magnesium content than dark (mafic) rocks.</span>
Hi,
Note that the "British pound" isn't a unit of weight (lb.) but rather a unit of currency. By weight, the lb. is the same (British or American), though Brits usually use grams or kilograms rather than pounds, for weight.
The currency conversion from the British pound (£) is roughly equal to $1.22
It's a type of fossil specifically called a 'Cast.'
