The Round Double Millgrain with Opal piece features a 2mm
synthetic Opal stone in the center adorned by two close-set rows of metal beads (millgrain). This threadless decorative end is available in 14 karat Yellow Gold, White Gold and Rose Gold options. Measuring 5.25mm x 5.25, it can be used in any piercing that is fit with a threadless post from all major jewelry vendors.
The second photo was taken by Jesus Cabanas aka Salabodymod.