Hedyphane



Hedyphane is a calcium lead arsenate chloride mineral of the apatite group. Rouse et al. (1984) showed that Ca and Pb are ordered in the structure with the ratio Pb:Ca = 3:2. The statement of [Dunn] (Dunn et al., 1980a) that much local material is calcian mimetite was superseded by his statement, in the study of Rouse et al. (1984), that mimetite is rare and that hedyphane is the predominant Ca-Pb-As apatite-group phase here. Numerous analyses of local material by [Dunn] were given by Rouse et al. (1984) showing the partial solid solution towards mimetite and turneaureite. Franklin hedyphane is a significant host for Sr in secondary veins.
Hedyphane was described from Franklin by Foshag and Gage (1925), and fine crystals were later described by Palache and Berman (1927) and Palache (1935). Hedyphane is not known from Sterling Hill, but at Franklin it is the most abundant secondary host for both Pb and As.
Hedyphane occurs as superb gray to colorless crystals, up to at least 3 mm, bipyramidal in habit, and tabular. Most hedyphane, however, is massive, granular, and orange to yellow orange or colorless, although gray material has been reported. The density is 5.85 g/cm3. The luster is decidedly greasy to adamantine. As first noted by Palache (1928b), hedyphane is fluorescent in ultraviolet. It has a moderate orange color in shortwave and a weak yellowish white color in longwave. It is best distinguished from other As-apatites by X-ray methods and chemical analysis.
Hedyphane occurs as a secondary vein mineral; its genesis is uncertain. The original occurrence was between the 500 and 600 levels in the east limb at Franklin, from which also came chlorophoenicite and schallerite. Here hedyphane occurred as white to colorless massive material, associated with green willemite, pink rhodonite, tarnished copper crystals, and calcite in veins in franklinite/willemite ore; fine, hexagonal, 6 mm, barrel-shaped crystals occur in this assemblage. Palache and Berman subsequently described fine crystals associated with cahnite, tabular willemite, barite, rhodonite, and manganaxinite from a vein assemblage.
Hedyphane occurs in a number of assemblages; only those generally recognized as being common are mentioned here. It occurs in a brecciated vein assemblage of barylite with copper, willemite, serpentine, and white, platy, curved calcite. It also occurs with andradite, rhodonite, and willemite in quite varied vein assemblages. Brownish "ribbon" veins of rhodonite crystals with hedyphane are not uncommon; many were mislabeled as schallerite in earlier years. In general, hedyphane has an apparent affinity for rhodonite; willemite and unstudied fibrous amphiboles are also commonly associated. (Dunn, 1995)


 Location Found: Franklin
     
 
 Year Discovered: 1830
     
 Formula: Pb3Ca2(AsO4)3Cl
 Essential Elements: Arsenic, Calcium, Chlorine, Lead, Oxygen
 All Elements in Formula: Arsenic, Calcium, Chlorine, Lead, Oxygen
     
 IMA Status: Approved
     
Fluorescent Mineral Properties

 Shortwave UV light: Orange weak
 Mid wave UV light: Orange, usually of moderate to weak brightness
 Longwave UV light: Very weak orange
     
 To find out more about this mineral at minDat's website, follow this link   Hedyphane

     
 References:
Dunn, Pete J. (1995). Franklin and Sterling Hill New Jersey: the world's most magnificent mineral deposits. Franklin, NJ.: The Franklin-Ogdensburg Mineralogical Society. p.650

Frondel, Clifford (1972). The minerals of Franklin and Sterling Hill, a checklist. NY.: John Willey & Sons. p.60


The Picking Table References
 PT Issue and PageDescription / Comment
V. 57, No. 2 - Fall 2016, pg. 19Fluorescent Minerals of Franklin and Sterling Hill, N.J., Part 1, Richard C. Bostwick - Hedyphane
View IssueV. 33, No. 2 - Fall 1992, pg. 10The Check List of Franklin-Sterling Hill Fluorescent Minerals - Hedyphane (Fluorescent Info)
View IssueV. 25 No. 2 - Fall 1984, pg. 9Mineral Notes Research Reports, Hedyphane
View IssueV. 18, No. 2 - September 1977, pg. 14The Fluorescent Minerals of Franklin and Sterling Hill, NJ by Richard C. Bostwick - Hedyphane
     
Images

     
Hedyphane, rhodonite, willemite and minor franklinite from Franklin, NJHedyphane, rhodonite, willemite and minor franklinite from Franklin, NJ under midwave UV Light
Hedyphane (tan), rhodonite (pink-tan), willemite and minor franklinite from Franklin, NJ. Photo by JVF.
Hedyphane, rhodonite, willemite and minor franklinite from Franklin, NJ under mid-wave UV light. The hedyphane fluoresces orange-red, willemite green, rhodonite and franklinite are non-fluorescent. Photo by JVF.
Hedyphane, rhodonite, willemite and minor franklinite from Franklin, NJ under shortwave UV Light
Hedyphane, rhodonite, willemite and minor franklinite from Franklin, NJ under shortwave UV light. The willemite fluoresces green, and the hedyphane, rhodonite and franklinite are non-fluorescent. Photo by JVF.







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