Russian Opal

VIS-NIR region of the spectrum (Fig. 5). White glass materials, commonly known as opal glass —the most familiar of these are the so-called Russian Opal (also known as MS-20 milk glass) and Japanese opal glass—are also frequently used by manufacturers of color measurement instrumentation (Fig. 6). 

FiQ. 6. 8° Hemispherical reflectance factor for Russian opal (specular included and excluded) and Japanese opal glass. 

A similar modern accumulation of silicon, as opal mineral, was monitored in Boreal Peat ecosystems in Belarussia and in floodplains of varions rivers in the Central Russian Plain. The biogeochemical mechanism of this silicon species formation is connected with the evapotranspiration of ground waters enriched in silicon by plants and deposition of amorphous silicon (Kovda, 1984). 

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