| Category | Silicate mineral |
|---|---|
| Formula | Ca7(Si3O9)2CO3·2H2O |
| Imasymbol | Scw[1] |
| Strunz | 9.CK.15 |
| Dana | 64.2.1.1 |
| System | Monoclinic |
| Class | Prismatic (2/m) (same H-M symbol) |
| Symmetry | C2/m |
| Unit cell | a = 10.12 Å, b = 15.18 Å c = 6.62 Å; β = 100.55°; Z = 2 |
| Color | Colorless |
| Habit | Platy - micaceous, parallel to radiating clusters |
| Cleavage | Perfect on {001}, poor on {010} |
| Mohs | 4–5 |
| Luster | Vitreous |
| Diaphaneity | Transparent |
| Gravity | 2.77 |
| Opticalprop | Biaxial (+) |
| Refractive | nα = 1.597 - 1.603 nβ = 1.606 - 1.609 nγ = 1.618 - 1.621 |
| Birefringence | δ = 0.021 |
| 2v | Measured from 74° to 78° |
| References | [2][3][4] |
Scawtite is a hydrous calcium silicate mineral with carbonate, formula: Ca7(Si3O9)2CO3·2H2O. It crystallizes in the monoclinic crystal system as thin plates or flat prisms.[3]
Scawtite was first described in 1929 for an occurrence at Scawt Hill in Northern Ireland.[3]
Scawtite occurs as in skarns and hydrothermal veins in limestone. Associated minerals include melilite, spurrite, tobermorite, thomsonite, larnite, grossular, bultfonteinite, calcite, analcime, foshagite and hillebrandite.[2]
References
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616
- ^ Scawtite in the Handbook of Mineralogy
- ^ Scawtite on Mindat.org
- ^ Scawtite data on Webmineral