"Castorite" Natural Recordings by Native Speakers
Castorite is a very rare mineral, a hydrated iron phosphate mineral with the chemical formula Fe3(PO4)2(OH)·6H2O. It was first described in 1869 and is named after the inventor of the blowpipe, Friedrich Müller, who is also known as "Castor". Castorite is a mineral of sedimentary origin, usually found in phosphate deposits, and it has a secondary crystal form with a white or yellowish color.