Hard Rock Lithium Deposits are also known as Pegmatite deposits. Pegmatite is a coarse-grained intrusive igneous rock formed from crystallized magma below the Earth's crust. Pegmatite lithium deposits can contain extractable amounts of a number of elements, including lithium, tin, tantalum and niobium.

Lithium in pegmatites is most commonly found in the mineral spodumene, but also may be present in other minerals such as petalite, lepidolite, amblygonite and eucryptite.