A Johnson Matthey 1000oz silver bar is an LBMA (London Bullion Market Association) bar. This is a silver bar that can be used to deliver against a futures contract and can be stored in any commodity exchange's warehouse. These bars are rarely exactly 1000oz in weight but their weight and purity are always stamped on the bar itself. In order for a silver bar to be LBMA approved, it must not only be 999 fine with its weight stamped on it, but also be produced by an accredited manufacturer like Johnson Matthey. The list of approved manufacturers can be found on the LBMA's documentation or also in most major exchange's rules books.

These extremely heavy (approximately 68.5 lbs) are mostly popular among large investors who are looking for low premium silver for investment. One of the challenges for smaller investors who buy these silver bars is where to store them given their weight and size. 

A Johnson Matthey 1000oz silver bar that is LBMA approved is IRA eligible.