Stibiotantalite is a strongly dispersive oxide mineral of antimony and tantalum. It is found primarily in complex granite pegmatites. If the quantity of niobium exceeds the tantalum content, the mineral is called stibiocolumbite.
It is translucent to transparent with a hardness of 5.5 on Moh's scale and an adamantine luster
The name Stibiotantalite reflects its antimony (Greek - stibi) content and similarity to Tantalite. It forms transparent or semi-transparent yellowish to brownish equant or flattened prismatic crystals. It is heavier, softer and brighter than tantalite.
Stibiotantalite can be cut into bright fiery golden-brown gems which have some resemblance to sphalerite.