* Chromitite: This rock is rich in the mineral chromite, which often contains platinum as a trace element.
* Dunite: This ultramafic rock is almost entirely composed of olivine, and can contain platinum-group minerals as inclusions.
* Norite and gabbro: These mafic rocks are also known to contain platinum, although in lower concentrations than other rocks.
Platinum is also found in placer deposits, which are formed by the erosion and concentration of heavier minerals like platinum in riverbeds and beaches. These deposits are often found downstream from areas where mafic and ultramafic rocks are exposed.
It's important to remember that platinum is extremely rare, and finding it in rocks is a challenging task. The vast majority of platinum is extracted from mining operations in South Africa, Russia, and other countries with large deposits of these specific rock types.