Contribution
Chrysoprase from Warrawanda, Western Australia
Nagase, T.; Akizuki, M.; Onoda, M.; Sato, M.
Neues Jahrbuch für Mineralogie - Monatshefte Jg. 1997 Heft 7 (1997), p. 289 - 300
15 références bibliographiques
publié: Sep 12, 1997
DOI: 10.1127/njmm/1997/1997/289
ArtNo. ESP156199707000, Prix: 29.00 €
Abstract
Chrysoprase from Warrawanda, West Australia, was observed using optical and transmission electron microscopies (TEM), Fourier transformation infrared spectroscopy (FT-IR) and electron microprobe analyses (EPMA). It was tried to identify origin of the green colour. TEM observations and IR-spectra analyses show that the chrysoprase includes kerolite, which occurs as a cotton-like aggregate of extremely fine-grained crystals at the boundaries of quartz grains and in quartz crystals. EPMA analyses show that the kerolite contains about 10 wt% NiO, and that NiO content of the chrysoprase increases with the degree of silicification of the surrounding serpentinite. The Ni-bearing kerolite derived from the silicified serpentine is inferred to cause the green colour of the chrysoprase.
Mots-clefs
Chrysoprase • kerolite • quartz