亦或是什么意思

A rock containing three crystals of pyrite

百度 得此全帖，赵孟頫如入宝山，八月，兴奋地作《阁帖跋》。

In crystallography, the cubic crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals.

There are three main types of these crystals:

• Primitive cubic
• Body-centered cubic
• Face-centered cubic

Types

Name	Description	Picture
Primitive cubic	One atom at each corner of the cube.
Body-centered cubic	One atom at each corner of the cube, and one in the middle of the cube.
Face-centered cubic	One atom at each corner of the cube, and one in the middle of each face (side) of the cube.