onecarat Stone measurement Baguette unit Typical solitaire size Typical solitaire diamond size Solitaire weight, perhaps Solitaire measure, maybe Like some solitaires Like many engagement stones Jeweler's hundred points Engagement-ring size, perhaps Like some diamonds, sizewise Like some engagement rings About three grains 200 milligrams, to a jeweler Common diamond measure About 2% of the Hope Diamond 200 milligrams Diamond figure? Like some diamonds 100 points