Photo: Wikimedia Commons

Unusual calcium silicate mineral with carbonate, sulfate and hexacoordinated hydroxysilicate anions. Responsible of a harmful concrete sulfate attack

Properties

Chemical formula

Ca₃Si(OH)₆(SO₄)(CO₃)·12H₂O

Group

Silicates

Crystal system

Hexagonal

Hardness (Mohs)

—

Color

Colorless

Luster

—

Streak

White

Density

—

Cleavage

—

Fracture

—

Tenacity

—

Crystal habit

—

Transparency

—

Space group

—

Fluorescence

—

Magnetism

—

Radioactivity

—

Refractive index

—

Optical character

—

Birefringence

—

Pleochroism

—

Strunz classification

7.DG.15

Dana classification

32.4.4.4

IMA status

Grandfathered mineral (G)

IMA symbol

Tma

Locality

🇸🇪 Åreskutan

Type locality

—

Discovery year

—

Source: Wikidata