Eclipse features an oversized, rose-cut and dome shaped black onyx set in 18k gold vermeil. A simple and elegant statement piece! Each earring's diameter is 27mm and the pair of earrings has a total of 100 carats of black onyx gemstone! The base metal of all our jewellery is 925 sterling silver. Vermeil means that sterling silver is plated in at least 2.5 microns of gold or rose gold. Ours is at least 3 microns of 18k gold / rose gold which makes for a really thick coating of gold / rose gold on sterling silver.