I know the bottom number on the Geneva hunter case crystals refers to the height. Can anybody please explain the other two measurements to me? I am used to going through my cabinet and finding one that fits but I have a chance to "order" some and need a clearer understanding. Thanks!

Robert your reference to "Geneva" crystals may throw this reply off because I have never heard of a "Geneva" measurement system.

I use a size chart (below) to determine the size code for any crystal I will fit to a measured seat diameter of a target Crystal bezel.

I am not sure what the units of diameter mean but the 1/16 graduations are real and they give each size a "true inch" value you can check with your measurements of the bezel seat diameter.

So for example if you measure a 1.645" (give or take a few thou) diameter. Consulting the chart gives you the corresponding printed label number for that diameter which in this case (1.645") is "18-8", or 18 and 8/16ths.

Thanks Dave. I am always fitting hunter cases with crystals and the labels have 3 numbers on them. I thought they were called Geneva crystals for some reason. I know the bottom number is height and I think the top one has to be the diameter where they seat but what is does the middle number mean? Hasn't ever made much difference when I just go through mine and find a good fit but now I am trying to tell somebody what I want. Thank you for the chart

Robert, the crystal sizing numbers you refer to including a "middle" number are puzzling. I am used to a top number and a bottom number on the crystal label. The top being the diameter according to the chart, and the bottom having to do with the dome height. For example, the 20 8/16 foreground crystal (below) would be 1.822 Inches in Diameter and have a "dome" of 21 (somethings).

What a coincidence. I just printed off Dave's chart this morning. I've looked at a lot of crystals online and didn't understand the numbers until I saw this post.
Thanks Dave!

Sorry it took me so long to reply Dave. Things have been hectic. I still haven't aced Picasa yet, to put it mildly , but I did figure out how to resize a picture again so I am attaching one of the labels I am talking about. Thanks for your invaluable input!

WOW! I hope someone can help with this dome measurement thing. I thought the higher the number the lower the dome, but who knows.