| Ussingite | |
| Category: | Phyllosilicate minerals |
| Formula: | Na2AlSi3O8OH |
| Imasymbol: | Usg[1] |
| Strunz: | 9.EH.20 |
| System: | Triclinic |
| Class: | Pinacoidal (same H-M symbol) |
| Symmetry: | P |
| Color: | pale to medium violet, reddish violet; sometimes barely tinted purple |
| Fracture: | irregular/ uneven |
| Tenacity: | brittle |
| Mohs: | 6–7 |
| Luster: | sub-vitreous |
| Streak: | white |
| Diaphaneity: | transparent, translucent |
| References: | [2] [3] |
Ussingite is a silicate mineral with formula Na2AlSi3O8(OH).[4]
It was named for Niels Viggo Ussing (1864–1911), Copenhagen, Denmark.