MIMETITE, CORONADITE, DUFTITE (EXTREMELY RARE)

SMALL NEEDLES: Mimetite is a mineral composed of lead arsenate chloride (Pb5(AsO4)3Cl) that typically forms as a secondary mineral in lead deposits through the oxidation of galena and arsenopyrite. Its name is derived from the Greek word Μιμητής mimetes, which translates to "imitator," highlighting its similarity to the mineral pyromorphite. This similarity is significant, as mimetite is part of a mineral series that includes both pyromorphite (Pb5(PO4)3Cl) and vanadinite (Pb5(VO4)3Cl). Noteworthy locations for mimetite include Mapimi in Durango, Mexico, and Tsumeb in Namibia.

GREY: Coronadite Pb(Mn⁴⁺₆Mn³⁺₂)O_{16 ,}  serves as the lead endmember of the hollandite group, which consists of tectomanganates characterized by a 2 × 2 tunnel structure. This extremely rare mineral is named in honor of Francisco Vasquez de Coronado, an explorer known for his journeys in the southwestern United States. The designation was introduced by Waldemar Lindgren in 1905.

GREEN: Duftite is a fairly prevalent arsenate mineral characterized by the formula CuPb(AsO4)(OH) and is closely related to conichalcite. Typically green in color, it often appears in botryoidal formations. As a member of the adelite-descloizite Group and the Conichalcite-Duftite Series, specimens from Tsumeb frequently exhibit zoned variations in both color and composition. Analytical techniques such as microprobe analyses and X-ray powder diffraction reveal significant substitution of Zn for Cu and Ca for Pb within the duftite structure, suggesting a solid solution relationship among conichalcite, austinite, and duftite, all of which are part of the adelite group of arsenates. The mineral is named in honor of G Duft, a Mining Councilor and Director of the Otavi Mine and Railroad Company in Tsumeb, Namibia.