I am close to pulling the trigger on a diamond. I have narrowed my search down to several ideal cut diamonds. However, I'm still not clear on the girdle thickness of some of them. Several of them have girdle sizes described in terms of thin to slightly thick, which I understand is good. However, some of the diamonds have the girdle described in numeric terms. One is 1.2 - 1.9. Another is .7 - 1.0. The third is 1.2 - 1.5. When the girdle is stated in numeric terms, what should I be looking for on an otherwise ideal diamond?