Skin anchor with gem.

Skin anchors are almost like dermal anchors, except that the top of skin anchors or divers cannot be interchanged, while the top of dermal anchors can.

This skin anchor has a diameter of 1/8" (3 mm), both on the top and the bottom plates. The distance between them is 1/16" (2 mm), and the gauge size is 16g (1.2 mm). You can choose the gem color you prefer. 

It's made of solid titanium and comes in a single piece, so there's no risk of losing the top.