Clutch back: post earring, spring grip closure. Lever back: hinged wire loop for drops and dangles, no separate piece needed. Different earring formats require different closure systems.
Stone Story
Black opal as a distinct commercial category emerged from Lightning Ridge's deposits in the early 20th century. The dark body tone was immediately recognized as producing play-of-color of unusual intensity compared to the lighter-bodied material that had dominated the market. Fine Lightning Ridge black opal established new per-carat price benchmarks that placed it among the world's most valuable colored gemstones.
Visually Speaking
Post findings are used across the earring formats designed for flush or near-flush earlobe wear. Studs, clusters, button earrings, and drop earrings with rigid top elements all rely on the post's perpendicular projection to hold the front element in its intended position against the lobe.