Connoisseur's Choice: Legrandite, Ojuela Mine, Mapimí, Durango, Mexico.

Adamite microcrystals and/or mixed iron-oxide pseudomorphs after adamite or legrandite are common on Ojuela matrix, but although adamite is known from Flor de Peña, it is not known in association with legrandite there, so this may be a diagnostic Ojuela indicator. Isolated freestanding crystals are common as are sheaves, sprays, and bundles of fibrous crystals to 8 cm long. Ojuela legrandites occur on a rich, red-brown vuggy gossan matrix, commonly with tiny adamite crystals in the vugs. The relationship between legrandite and adamite (and paradamite?) is apparently not a happy one as shown by groups of goethite pseudomorphs after robust legrandite crystals to 3 cm across and 12 cm long, and 5-cm-diameter (fig. 8) adamite balls with hollow internal molds where legrandite crystals 1.5 cm across and at least 3 cm long once resided. Orange-yellow crystals of legrandite associated with scalenohedral crystals of pink smithsonite, 4 cm, from the so-called zinc pocket, 44 level, in the third oxidation zone of the Tsumeb deposit. [Extracted from the article]