Niobium is very similar to titanium. They’re both elemental metals, corrosion resistant, biocompatible, and hypoallergenic.
It’s a bit heavier than titanium and more expensive to produce. Niobium is silver in colour, but can be anodized into a range of fun colours.
Niobium is ideal for body jewellery as it is soft and malleable enough to make insertion easy, but strong and durable enough to resist scratches that can harbour bacteria.