I’ve had this very old rare mortar for many yrs. I’ve had it looked at by Butterfields Auction in San Francisco, who referred me to the natural museum in San Francisco and Sotheby’s. I’ve also had it looked at by professional appraisers who all concur it’s over 2000 yrs old but can’t more specifically date it because they’re not experts in identifying the figures carved in it. I’ve sent photos to Sotheby’s who said they couldn’t help me because they don’t have any auctions for this type of antiquity. I’ve also been told by the professional appraisers that it is museum quality. I just don’t know where I can get more info so I can sell it.