"Rock of the Month # 131, posted May 2012" ---

Vanadinite, ideal formula Pb₅(VO₄)₃Cl, is an hexagonal member of the apatite group. It is isostructural with the pyromorphite-mimetite group (Pb₅(PO₄)₃Cl- Pb₅(AsO₄)₃Cl) and forms short to long prismatic crystals, which may be variously cavernous, hollow or skeletal (Palache et al., 1951, pp.877,895-898). Vanadium (like chromium and uranium) as an element is parental to numerous, often highly-coloured mineral species (Evans and White, 1987).

Specimens from Morocco are well-known (e.g., Hofmann and Karpinski, 1981). Vanadinite is also noted from other localities, most notably in Arizona and adjacent New Mexico and Chihuahua, Mexico. It is also reported from: California; Nevada; Idaho; Argentina; Scotland, Wales and England (including Roughtengill in the English Lake District); Austria; Italy; Spain; Zambia; Namibia; India; and elsewhere.

There is a long history of mining in the area of the eastern Anti-Atlas mountains. The Imiter district has produced many specimens of silver minerals and associated species, including native silver and proustite, acanthite, galena, cinnabar, imiterite (Ag₂HgS₂), lavendulan (a blue arsenate of sodium, calcium and copper), mimetite and polybasite (Barral et al., 2011). The Bou Azzer district is known for at least 215 mineral species (Favreau et al., 2007). The diversity is due to chemically diverse metallic ores weathering to a plethora of secondary salts. There are ores of cobalt and nickel, with traces of bismuth, arsenic, tungsten, molybdenum, etc. Minerals include azurite, brochantite, pink cobaltian calcite, aragonite, celestite (celestine) gersdorffite, goethite, magnetite, scorodite, coarse skutterudite crystals in calcite (Tamdrost mine), sphaerocobaltite on quartz (from Agoudal), stichtite and more.

A variety of Moroccan mineral species recur as fine specimens at mineral shows year after year. Victor Yount was a pioneer in the marketing of Moroccan specimens (Moore, 2012). Notable Moroccan minerals, illustrated in the pages of Mineralogical Record in particular, include:

• Acanthite from Imiter (Moore, 2005; Polityka, 2005)
• Anglesite from, e.g., Touissit (Wilson et al., 1992; Wilson, 1988, 2011)
• Azurite from Touissit (Wilson et al., 1992; Larson, 2010)
• Cerussite, such as snowflake cerussite from Taouz (Larson, 2004)
• Erythrite (Moore, 2000; Larson, 2010; Wilson, 2011)
• Fluorite (Larson, 2010)
• Malachite (see azurite, e.g., Larson, 2010)
• Mimetite (Barral et al., 2011).
• Silver (native Ag and other Ag minerals from Imiter: Barral et al., 2011)
• Skutterudite (Trinchillo, 2008)
• Sphaerocobaltite (cobaltian calcite or cobaltocalcite, cobalt carbonate, from Bou Azzer: Larson, 2004; Wilson, 2009; Moore, 2012)
• Vanadinite from, e.g., Mibladen (Wilson et al., 1992; Moore, 1998; Scovil et al., 2001; Trinchillo, 2008; Wilson, 2011)

Acknowledgements. With thanks to Irwin Kennedy and Wanda Zyla, whose peregrinations have brought to light numerous fine mineral specimens, and extended knowledge of some far-flung mineral localities. Other examples of their material on these pages are: calcite from Mexico and galena with orpiment from Peru. Further samples from Morocco will follow shortly, including mimetite, sphaerocobaltite and cerussite.

References

Barral,J-P, Favreau,G and Lheur,C (2011) Imiter: Morocco's greatest silver mine. Mineral.Record 42, 107-135.

Evans,HT and White,JS (1987) The colorful vanadium minerals: a brief review and a new classification. Mineral.Record 18 no.5, 333-340.

Favreau,G, Dietrich,JE, Meisser,N, Brugger,J, Haddouch,LA and Maacha,L (2007) Bou Azzer, Morocco. Mineral.Record 38, 345-407.

Hofmann,F and Karpinski,J (1981) Rare and Beautiful Minerals. Exeter Books, N.Y.C., Engl. transl. of Ger. original, 226pp.

Jensen,M (1982) Endlichite and descloizite from the Chalk Mountain mine, Churchill County, Nevada. Mineral.Rec. 13 no.4, 219-221.

Larson,B (2004) Sainte-Marie aux Mines show 2003. Mineral.Record 35, 145-148.

Larson,B (2010) Sainte-Marie-aux-Mines Show 2010. Mineral.Record. 41, 541-546.

Moore,T (1998) Tucson Show 1998. Mineral.Record 29, 209-221.

Moore,T (2001) Denver Show 2000. Mineral.Record 32 no.1, 56-63.

Moore,T (2005) Munich show 2004. Mineral.Record 36, 117-121.

Moore,TP (2012) Victor Yount and his calcite collection. Mineral.Record 43, 85-97.

Palache,C, Berman,H and Frondel,C (1951) The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana. Volume 2, Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. John Wiley and Sons, Inc., New York, 7th edition, revised and enlarged, 1124pp.

Polityka,J (2005) Springfield show 2004. Mineral.Record 36, 109-113.

Scovil,J, Larson,WF and Polityka,J (2001) What's new in minerals. Mineral.Record 32, 487-497.

Trinchillo,D (2008) The Marc P. Weill collection of fine minerals. Mineral.Record 39 no.1, supplement, 96pp.

Wilson,WE (1980) Famous mineral localities: Los Lamentos, Chihuahua, Mexico. Mineral.Record 11 no.5, 277-286.

Wilson,WE (1988) What's new in minerals? Mineral.Record 19 no.3, 209-218.

Wilson,WE (editor) (2009) Private Mineral Collections in Texas. Mineral.Record 40 no.1, supplement, 180pp.

Wilson,WE (editor) (2011) Private Mineral Collections in Italy. Mineral.Record 42 no.1, supplement, 144pp.

Wilson,WE, Bartsch,JA, Van Pelt,H and Van Pelt,E (1992) Minerals of the Houston Museum of Natural Science. Mineral.Record 23 no.1, supplement, 34pp.