Which preposition to use with carat

to Occurrences 2%

The sapphires ran from fifteen carats to sixty, and there was not a flaw amongst them.

as Occurrences 1%

You may interpret the carat as a dagger in the original except in one place, where the carat itself is defined in the Special Characters List in section 550.

in Occurrences 1%

Mr. G.F. Breed, manager of the Valencia Mica Company, has cut nearly one hundred aquamarines, ranging from ½ carat to 4 carats in weight, and of a light blue color, from white beryls found in the company's mica mine at North Grafton, N.H.

of Occurrences 1%

And yet, I'll exchange three hundred carats of mint, Mr. Britt, for a dozen boxes of your Egyptian deities.

Which preposition to use with  carat