|Mineral class||Sulphides : Tetrahedrite bournonite boulangerite group|
|Habitus||Crystals are tabular and prismatic, often striated creating a cogwheel shape. Commonly in granular aggregates or massive.|
|Cleavage||Poor, fracture subconchoidal.|
|Hardness||2.5 - 3|
|Density||5.8 - 5.84|
|Color||Silvery gray to black, opaque.|
|Description||A minor ore of lead, mostly used for mineral specimens.|
|Associates||Siderite, galena, fluorite, sphalerite, pyrite and calcite.|
Type locality : Wheal Boys, St. Endellion, Cornwall, England.|
Bournonite often develops a grayish tarnish.
|Locations|| A common mineral worldwide but with few localities in Sweden.|
| To sulphides index.
|| Mineral group index.
If you have some questions, suggestions or comments you are welcome to write me a line or two.