he grading and evaluation standards of rubies are mainly based on 1T and 4C: 透明性, 色, 明確さ, カット, とカラット. 1. 透明性: refers to the degree to which a gemstone allows visible light to pass through. In the visual identification of rubies, transparency is generally divided into five levels: 透明, 半透明の, 半透明の, sub-translucent, そして不透明. […]
