Some gems have strong pleochroism. 例えば, andalusite has strong trichromaticity of brown, brown-yellow, and brown-green visible to the naked eye, which can be used as the identification feature of andalusite. The pleochroism of gemstones increases the beauty of gemstones. 例えば, tanzanite has pleochroism of blue and purple, which makes blue tanzanite look more […]
