Some gems have strong pleochroism. ตัวอย่างเช่น, 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. ตัวอย่างเช่น, tanzanite has pleochroism of blue and purple, which makes blue tanzanite look more […]
