The iron and manganese amounts vary considerably without much effect on properties. However the two end members are recognized as distinct minerals although collectors have found this to be rather cumbersome and generally prefer tantalite to the non-unique names of ferrotantalite and manganotantalite. Tantalite has a dimorphic relationship to another mineral called tapiolite. A dimorph is a mineral that has the same chemistry but a different structure. As mineral specimens, tantalite can be a nice addition to one's collection.
Good crystals are both complex and handsome.
Although the color selection is usually limited too black to brown the luster is generally good. Manganese rich tantalites can be brown and translucent. Color is dark black, iron-black to dark brown or even reddish brown. Luster is submetallic to almost resinous. Crystals are nearly opaque being transparent in thin splinters.