EK57AI9: Milpillas Volborthite specimens are without doubt the world’s best: with their large crystal size and high luster they set a new standard for this rare species. This small specimen shows a rosette-shaped growth of flattened Volborthite crystals on matrix; the rosette is very sharp and deeply colored.
The sample has been noted and photographed in the monograph 'The Milpillas Mine' of the ‘Mineralogical Record‘ magazine on page 619 in the volume 52, number 5, September-October 2021
Milpillas Mine, level 26, Cuitaca, Municipio Santa Cruz, Sonora  Mexico (04/2015)

Specimen size: 1.3 × 1.3 × 0.7 cm = 0.51” × 0.51” × 0.28”