It is a line drawing material of a gem made a long time ago.
Most of them are drawn with reference to real-life gem cuts, but there are some creative cuts.
Examples of use

It is painted appropriately and the transparency of the line drawing is appropriately reduced.
The size has been changed.
昔作った宝石の線画素材です。
ほとんどは現実にある宝石のカットを参考に描いていますが、一部創作のカットがあります。
使用例

適当に塗って適当に線画の透明度を下げたものです
大きさは変更しています
Gemstone Material 宝石素材