Polychroism of jewel chrome-diopside from the Inagli deposit (Yakutia) and the techniques of its sorting and faceting

Ivanov M. A.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2015. V. 144. N 6. P. 114-126

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Language: Russian

Abstract

Spectrometric study of the color of jewel chrome-diopside was carried out in plates oriented perpendicularly to directions of light waves absorption — by (100), (010), and perpendicular to the axis [001]. The experimental determination of the spectral absorption of light has allowed to calculate co lorimetric parameters of the mineral and to characterize its polychroism. While translucency in rays of ordinary light in the [001] direction its color is the clearest green, in the [010] direction—green with a yellowish tint, in direction perpendicular to the plane (100)—green with yellow-brown shade. Differences of coloring in the directions perpendicular to the axis [001] are considerably lesser. And the transparency (lightness) of the mineral is higher in directions perpendicular to the crystallographic axis [001]. Thus, the principal sorting of this mineral by its color has to consider its crystallographic orientation in the cutting process.

Key words: chrome-diopside, absorption spectra, colorimetry, polychroism, jewelry production.