Mô tả - Bề mặt bị tách thành phiến, vảy khi cắt ngang. - Rất khó nhận dạng bởi vì bề mặt không bị nứt. - Bề mặt thường hư khi dùng vật cứng cào nhẹ vào.
Description-the surface was ripped up, scales when cut. -Very hard to identify because the surface is not cracked. -The surface is often damaged when using hard objects on the scratch.
Description - The surface is separated into sheets, flake when cut. - Very difficult to identify because the surface is not cracked. - The surface is often damaged when using hard objects scratch lightly.