trachyte
Concise Oxford English Dictionary © 2008 Oxford University Press:
trachyte /ˈtreɪkʌɪt, ˈtrakʌɪt/
▶noun Geology a grey fine-grained volcanic rock consisting largely of alkali feldspar.
– origin C19 (orig. denoting a volcanic rock with a gritty surface): from Gk trakhus ‘rough’ or trakhutēs ‘roughness’.
'trachyte' also found in these Oxford entries:
