This is a replica of an Ichiryo Koban (one-ryo gold coin) cast between Genbun 1 (1736) and Bunsei 1 (1818). (With a "bun" mark in true script on the back) - Material: Unknown (Possibly brass?) - Weight: Approximately 12.2g - Dimensions: Approximately 72mm x 39mm x 0.6mm (Please note that these measurements are amateur measurements taken with a commercially available measuring device, so there may be some error.) There are fine scratches, so please refrain from purchasing if you are concerned. This is just a replica, but please add this popular Koban gold coin to your collection for good luck with money! Thank you for viewing.