Lithium-rich pegmatite, Sinclair mine, WA Collection Highlights | Updated 1 years ago Pegmatite from the Sinclair mine near Norseman, Western Australia. Specimen is 88 cm long. Peter Downes, WA Museum This colourful polished slab of lithium-rich pegmatite, 88 cm long, is from the Sinclair mine near Norseman, WA. Commonly, pegmatites are found as dykes cutting through surrounding rocks. Crystals of lithium-rich petalite up to an astonishing 20 metres long occur in the Sinclair pegmatite. Many of WA’s pegmatites crystallized as the final products of solidifying granitic magmas in our ancient continental crust. Pegmatites may be rich in elements like lithium, cesium, beryllium and niobium, that are important to our high-tech world. Rock Collection