pipe opal

Fetched 2026-10-26 (cache).

Synonyms: fire opal, piperonal

Antonyms: fire opal, piperonal

Related words from Datamuse; suggestions, not definitions.

Noun

1. {{lb|en|mineralogy}} {{1|opal}} formed in an unusual tubular shape, mainly in [[sandstone]].

Source: Wiktionary · CC BY-SA 4.0 (Wiktionary dump) · cached copy, not a rewrite.