The shape of ore deposits, their dimensions, depend heavily on their origin. They also have a very clear influence on the methods of mining the ore. Mineralized columns naturally have 3 dimensions in space. Depending on the ratios of these 3 dimensions, three types of shapes can be distinguished:
- Isometric bodies where the 3 dimensions are approximately equal (masses and nests, pockets and balls, lenses);
- Bodies with the shape of columns, where one dimension is much larger than the other two (length exceeds width and power).
They are rarely encountered and were always formed after the enclosing rocks;
- Bodies with the shape of slabs, where two dimensions are large (length and width) and the third (power) is small. Veins, layers and blades are part of this category.
✅ Veins
A vein is used to describe a mineral mass that fills a rock fissure. It is encased in rocks formed before the phenomenon of filling the fissure, crack and cavity with mineralized matter.
✅ Layers
A layer is a mineralized body in the form of a slab, of sedimentary origin, which is separated from other rocks by the flat surfaces of stratification, the hanging walls. Layers are formations that formed at the same time as the rocks that contain them, which distinguishes them from veins.
✅ Mass (stock)
Here, the mineralized body is more or less isometric homogeneous or almost homogeneous. It is the impregnation of magmatic, metamorphic rocks and the substitution of sedimentary rocks.
✅ Stockwerk
A stockwerk is used when the rock mass is anastomosed by fine veins loaded with disseminated mineral substance. This is usually the feeding zone located on the periphery of the masses (stocks).
✅ Disseminated (Porphyry copper)
This is a mineral substance disseminated in the host rock in the form of small grains (flies).
