Abstract

An edingtonite crystal from Ice River, British Columbia, Canada, has a clear, euhedral rim and whitish, anhedral core. The rim shows the m{110}, o{111}, p{111}, and c{001} sectors and a small 2V value (about –22°) with some exceptions in the {111} sector, and the core shows twinning without sectors and a large 2 V value (about – 52°). X-ray diffraction analysis indicated that both the core and the rim are orthorhombic. However, optical observation leads to a different conclusion: the core is orthorhombic and consists of an ordered Al-Si structure, whereas the rim, especially the {110} sector, is evidently triclinic and has a partly ordered structure.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.