IPA: //ˈfɛlstoʊn//
KK: /ˈfɛlstoʊn/
A type of fine-grained volcanic rock that is similar to felsite.
The geologist collected samples of felstone for further analysis.
The word 'felstone' originates from Old English 'fæl' (meaning pale or light) and 'stan' (meaning stone). It refers to a type of stone that is pale in color.
Think of 'pale' ('fæl') and 'stone' ('stan') to remember that 'felstone' refers to a pale-colored stone.