Definition of needlestone in English:

needlestone

noun

Mineralogy
historical
  • A form of zeolite with needle-like crystals; mesotype.

Origin

Early 19th century; earliest use found in Robert Jameson (1774–1854), geologist and natural historian. From needle + stone, after German Nadelstein.

Pronunciation

needlestone

/ˈniːdlstəʊn/