KITTATINNYITE

Ca₄Mn³⁺₄Mn²⁺₂Si₄O₁₆(OH)₈.18H₂O
Hexagonal, P6₃mmc, P6₃mc, or P2c, a = 6.498, c = 22.78 Å,
Z = 1

	Figure 18-38. Crude platy kittatinnyite crystals from Franklin. Field of view is 0.3 mm in maximum dimension.

Kittatinnyite was described from Franklin by Dunn and Peacor (1983a). It was originally found in 1874 in the Taylor Mine, which became part of the Franklin Mine. It has not been reported from Sterling Hill. The crystal structure is unknown.

Description

Kittatinnyite occurs as sparse, composite, subparallel aggregates up to 0.5 mm in diameter; individual crystals are flattened on [0001] and very thin (Figure 18-38). Kittatinnyite is bright golden yellow, resembling specks of native gold in hand-specimen. The luster is vitreous; the density is 2.61 g/cm³; cleavage is perfect on {0001}; and the mineral is brittle. Optically, kittatinnyite is uniaxial, negative, with w = l.727, and weakly pleochroic. There is no discernible fluorescence in ultraviolet.

Composition

Kittatinnyite is a calcium manganese silicate hydroxide hydrate mineral. A microprobe analysis is given in Table 15. Assumptions about the oxidation state of the cations are given by Dunn and Peacor (1983a). The formula is tentative and calculated in part based on the analogy to the isostructural wallkilldellite. This relation to wallkilldellite is the first known natural example of As/Si analogues in layer structures.

Occurrence and paragenesis

Kittatinnyite is known only on one specimen from Franklin. It is found on the type specimen for bostwickite on medium-grade ore consisting of franklinite, calcite, and fluorite. Bostwickite is on one side of the specimen; kittatinnyite is on the other. Kittatinnyite is a very rare mineral.

Name

Kittatinnyite is named for the Algonquin word kittatinny, which means “endless hills,” in allusion to the topography of the area around Franklin and Sterling Hill.

Copyright © 1995 by Pete J. Dunn			Website by Herb Yeates
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This page created: January 14, 2001