Formula: Zn₂(PO₄)(OH)

Colour: White, colourless, yellow, red green or brown; colourless in transmitted light.

Lustre: Vitreous, Pearly

Hardness: 3½

Specific Gravity: 4.12

Crystal System: Triclinic

Member of: Tarbuttite Group

Name: Named after Percy Coventry Tarbutt (1943-), a Director of the Broken Hill Exploration Company who collected some of the first specimens at Broken Hill (now Kabwe), Zambia.

Type Locality: Kabwe Mine (Broken Hill Mine), Kabwe (Broken Hill), Kabwe District, Central Province – Zambia

A rare secondary zinc phosphate.