Term |
Definition |
| Alluvial |
Diamond deposits located in sediments transported by river or marine systems. |
| Artisanal |
Small scale, informal and non-mechanical mining operations. |
| Audit |
Checking mechanisms to verify the veracity of results. |
| Autolith |
Pellet-shaped kimberlite inclusion within a kimberlite. |
| Barren |
A kimberlite which does not contain diamonds. |
| Basalt |
A fine-grained, basci extrusive igneous rock. |
| Block model |
A modelling technique which divides the resources into a number of mineable blocks. |
| Bottom cut-off screen size |
Smallest screen, mesh size, which separates ore to be processed from fines to be discarded. |
| Breccia |
A clastic sedimentary rock consisting of coarse, angular fragments. |
| Bulk sample |
A large sample processed through a small-scale plant and not in a laboratory. |
| Calcite |
A carbonate mineral with the chemical formula CaCO3 |
| Carat |
Unit of weight for diamonds, 0.2g = 1 carat |
| Chlorite |
A heterogenous group of greenish minerals consisting of layer lattices. A product of low grade metamorphism, e.g. Talc. |
| Chrome-diopside |
One of the clinopyroxene group of minerals, commonly found in igneous rocks. The chrome end-member of the group often found in kimberlites. |
| Diamond drilling |
A drilling method where the rock is cut with a diamond encrusted bit to extract core. |
| Diamond grade |
The content of diamonds, measured in carats, within a volume or mass of rock. |
| Diamondiferous |
Containing diamonds |
| Diatreme |
A volcanic vent, formed by the intrusion of cool gas-fluidised rock, rather than magma. |
| Dolerite |
A medium-grained igneous rock emplaced within the earth's crust in the form of dykes and sills. It has the same mineralogy as basalt. |
| Ferrosilicon |
Heavy powder, which, when mixed with water, form the dense medium in a Dense Media Separator Plant andis recovered using its magnetic property. |
| Flocculant |
Chemical additive used as a thickener in a Dense Media Plant to precipitate slimes and thereby recover clear water |
| Garnet |
A silicate mineral. The magnesium-rich variety, pyrope, is commonly found in kimberlites. |
| Glove box |
Sealed box which is used to sort diamonds. |
| Grade |
The relative quantity or percentage of diamonds within the rock mass. |
| Indicated diamond resource |
That part of a diamond resource for which tonnage, densities, shape, physical characteristics, grade and average diamond value can be estimated with a reasonable level of confidence. It is based on exploration sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are too widely or inappropriately spaced to confirm geological and/or grade continuity but are spaced closely enough for continuity to be assumed and sufficient diamonds have been recovered to allow a confident estimate of average diamond value. |
| Inferred diamond resource |
That part of a diamond resource for which tonnage, grade and average diamond value can be estimated with a low level of confidence. It is inferred from geological evidence and assumed but not verified by geological and/or grade continuity and a sufficiently large diamond parcel is not available to ensure reasonable representation of the diamond assortment. It is based on information gathered through appropriate techniques. |
| Kimberlite |
An ultra basic rock defined as a porphyritic alkalic peridotite containing phenocrysts of olivine and phlogopite. Occurs as dykes or as characteristically carrot-shaped pipes. |
| Micaceous |
Rock containing a large portion of mica, a layer lattice group of minerals. Used to describe kimberlites rich in phlogopite mica. |
| Olivine |
A silicate mineral commonly found in igneous rocks. Typical of non-micaceous kimberlites. |
| Primary deposit |
With reference to the deposition of diamonds, these deposits include kimberlite pipes, dykes, blows and fissures as well as lamproites. Contrasted with alluvial deposit. |
| Slimes |
The fine fraction of tailings discharged from a processing plant without being treated. In the case of diamonds, usually that fraction is less than 1mm in size. |
| Sort house |
Area of the plant where final recovery and sorting of diamonds takes place. |
