Merelani

Merelani, also spelled Mererani, is a locality in northern Tanzania best known for the Merelani Hills, a gem-rich upland area in Simanjiro District of the Manyara Region near the foothills of Mount Kilimanjaro. The hills form one of Tanzania’s prominent gemstone districts and are the source of a high-value, globally significant gem.

The area is renowned for tanzanite, a blue‑violet variety of the mineral zoisite. Tanzanite crystals occur in hydrothermally altered nepheline-syenite intrusions within the Merelani belt, and the stones are typically found in small, high‑quality crystals. Since its discovery in the 1960s, the Merelani fields have supplied the majority of the world’s tanzanite. Mining is predominantly artisanal and small‑scale, with periods of more formal industrial activity by specialized mining companies. Because natural tanzanite’s color is enhanced by heat treatment, most commercially available stones are treated to intensify the blue hue.

Economically, the Merelani deposit has shaped Tanzania’s gem trade, attracting rough‑stone buyers, cutters, and traders. The site faces challenges common to artisanal mining, including safety, environmental impacts, and regulatory issues, prompting periodic government licensing and oversight efforts. Merelani remains a symbol of Tanzania’s gem industry and a key reference point in discussions of colored gemstones and African mining.