| Homilite | |
| Category: | Nesosilicate |
| Formula: | Ca2(Fe2+,Mg)B2Si2O10 |
| Imasymbol: | Hom[1] |
| Strunz: | 8/B.29-30 |
| System: | Monoclinic |
| Class: | Prismatic (2/m) |
| Symmetry: | P21/b |
| Unit Cell: | a = 9.78 Å, b = 7.61 Å, c = 4.78 Å; β = 90.56°; Z = ? |
| Color: | Greenish to brownish black |
| Mohs: | 5– |
| Luster: | Vitreous, resinous |
| Diaphaneity: | Opaque |
| Gravity: | 3.34 |
| Opticalprop: | Biaxial (+) |
| Refractive: | nα = 1.715 nβ = 1.725 nγ = 1.738 |
| Birefringence: | δ = |
| 2V: | Measured: 80° |
| References: | [2] [3] [4] |
Homilite is a borosilicate mineral belonging to the gadolinite group of minerals with formula .
It occurs as brown monoclinic crystals (space group P21/a[5]) within feldspar masses in pegmatite and was discovered in 1876 in Stoko island, Langesundfiord, Norway. The name is from the Greek for to occur together, in allusion to its association with meliphanite andallanite.