Terms

Large, low- to medium-grade disseminated deposits associated with porphyritic intrusions. Major sources of copper, molybdenum and gold globally.

Igneous texture with large phenocrysts in a finer groundmass, typical of magmas hosting porphyry systems.

Ratio of void space to total volume in rock or soil. Influences permeability, groundwater flow and heap-leach performance.

Entrance to an underground mine, usually horizontal or inclined, providing access to declines and workings.

Potassium-bearing salts (e.g., sylvite, carnallite) used in fertiliser production. Major deposits occur in evaporite basins.

Geophysical survey measuring gravity or magnetic fields to infer subsurface structure and ore bodies.

Unit of concentration equal to 1 mg per kg. Common for trace-element geochemistry and low-grade assays.

Large-diameter diamond-drill core (85 mm) that improves sample recovery, geotechnical quality and metallurgical testing.

Process stage that upgrades ore by rejecting waste before grinding, using methods such as ore sorting or gravity separation.

High-value metals such as gold, silver, and PGMs used in jewellery, investment, catalysts and electronics.

Material containing sulphides capable of producing acid mine drainage when exposed to air and water. Requires appropriate storage and treatment.

Concentrate produced by panning or gravity separation, used in early exploration to identify heavy minerals such as gold.