| When both the crystal form and structure are retained, the substances are said to be isomorphous. |
| Haematite crystallizes in the rhombohedral system, and is isomorphous with corundum. |
| It is rhombohedral in crystallization and isomorphous with calcite and chalybite. |
| Its salts are isomorphous with those of alumina and sesquioxide of iron. |
| It crystallizes in the orthorhombic system and is isomorphous with stibnite, which it closely resembles in appearance. |
| This also allows for the possibility of the application of phase improvement methods such as isomorphous noise suppression. |
