shagreen

1.shagreen Untanned sharkskin retaining the placoid scales;

鲨鱼皮保留盾鳞未鞣制鲨鱼皮；

2.(3) the observations and determination methods of form, cleavage, Becke line, shagreen surface, relief, pseudo-absorption, absorption, color, pleochroism of minerals under plane polarized light;

⑶单偏态、解理、多色性、吸收性、糙面、突起、贝克线等观察与测定方法；