I found the original gorgeous cowrie that became this necklace on the uninhabited island of Samson in The Isles of Scilly - I have spent many hours searching on the beautiful white stretch of sand there! It comes on a 1mm sterling silver snake chain. The shell measures approximately 10mm x 8mm. This wonderful shell pendant is also available in a larger size of 13mm x 10mm. Please specify chain length and size of cowrie when ordering. This piece is also available in 9ct yellow gold, see item 9ct Yellow Gold Cowrie Shell Pendant - Small. For 18ct yellow gold, please enquire via the Contact page.