Nigerite is very rarely found in gem-quality, cut-able material. Related to, and similar to,
Taaffeite, it contains tin instead beryllium.
In mineralogy, the name Nigerite refers to a group of minerals, Ferronigerite-2N1S and Ferronigerite-6N6S being the most common.
Data refers to the Ferronigerite-2N1S mineral, as it is the most likely to be found as cut gems.