Measures 3/4"+ all the way around, gets to 19.3mm in places but looks pretty round to me. Has a single sparkle 1/2 moon otherwise as nice as the day it was made. Top notch marble. Never a reserve. 99p starting price. Please, no best offers. True marble auctions. Guaranteed I.D's and dates of manufacture to the best of known information. All measurement are done with a micrometer to the best of my ability. Please see detailed pics for condition. I try very hard to show all aspects... of the marbles surface. In doing so tiny little flaws end up looking quite monstrous, but that is my aim. Macro pics also show in vivid detail, makers marks, surface texture and ripples, surface debris, tiny bubbles and even their shadows in some pics. In your hand these details are much harder to see. Under-lit pictures show color and in some cases the transparency of the base. Some are just for fun. If you have any questions please feel free to ask. Combined shipping is no problem. Please wait for an adjusted invoice that should arrive right after the last auction ends. Happy bidding. *********** U.S POST OFFICE BOX HOLDERS PLEASE READ ********* INTERNATIONAL AS WELL ********* Royal Mail does not offer either "Signed For" nor "Tracked" shipping services to P.O Boxes. The best shipping would be Royal Mail First Class service insured. This is fast and very dependable but not trackable or signable. Please keep this in mind. Thank you and sorry any inconvenience.