Goodness Anelle!! Please do not be so generous with the extremely sincere rating. We have accentuated the size of the stone may be we were not generous enough with the size!!! We have come to learn that there are omnifarious clients on bob. We sincerely hope you have many euphoric hours browsing or shopping on bob.YO! Anelle the following abbr mm is millimetre Cm is centimetre.; Please let us know if you would like a ruler( liniaal)