hydroxylherderite

hydroxylherderite

[hī¦dräk·səl′hər·də‚rīt]
(mineralogy)
CaBe(PO4)(OH) A monoclinic mineral composed of a phosphate and hydroxide of calcium and beryllium; isomorphous with herderite.
References in periodicals archive ?
Especially since World War II, the pegmatites of the state of Minas Gerais have yielded some of the world's finest specimens of topaz, chrysoberyl, euclase, elbaite, and beryl (in all of its colored varieties); phosphate-rich pegmatites of the same state have furnished the world's finest specimens of brazilianite, beryllonite, eosphorite, hydroxylherderite, amblygonite and more; complex pegmatites of other kinds have provided cassiterite, xenotime, monazite and several rare-earth species; Brazilian specimens of titanite, phenakite, fluorapatite, kyanite, scheelite, spessartine and bertrandite are among the world's very best.
br) had about a dozen miniature and small cabinet-size specimens of hydroxylherderite horn Virgem da Lapa, Minas Gerais, with lustrous, sharp, twinned crystals, color-zoned in pale violet and pale brown, to 4 X 8 cm, the matrix pieces showing attractive associations of sparkly white albite crystals and muscovite rosettes.
Hydroxylherderite is a rare accessory mineral, found normally close to or inside the tourmaline-bearing cavities.
Jeff had two flats of these specimens, all miniature-size; additionally, he had 15 nice thumbnails and miniatures of hydroxylherderite found, also last December, somewhere near the village of Shengus, in Skardu, about 2 km north of Bulochi.
In 1976 around 20 superb crystals of lustrous, lavender hydroxylherderite were found in Brazil, virtually redefining the species for collectors.
Frank and Wendy Melanson of Hawthorneden had a different version of an old standard: hydroxylherderite twins from Brazil.
A new prospect at Sabsar, Rhondu District, Northern Areas, Pakistan, has lately been giving up some fine little hydroxylherderite specimens: either sharp, lustrous, loose wedge-terminated prisms, essentially colorless but tinted yellowish gray by inclusions, or else, in a small minority of the specimens, pale green doubly terminated hydroxylherderite crystals to 2 cm lying flat on a matrix of white feldspar and black schorl, some with tiny gemmy colorless topaz crystals too.
Lacking analyses, it must be assumed to be hydroxylherderite.
The classic locality of Virgem de Lapa, Minas Gerais, Brazil, may once again be producing hydroxylherderite.
Mike Jacobs and Robert Hinkley have been the principal miners at the well-known Bennett quarry in Buckfield, where continued mining has provided hydroxylherderite crystals (to 2 cm), exceptional cleavelandite (albite) crystal groups (to 30 cm), attractive coatings of cookeite rosettes, microlite crystals of unusual dodecahedral form (to 2 cm), and numerous excellent quartz crystals, including some very attractive smoky quartz scepter growths on clear to milky quartz crystals (to 15 cm).