I am considering creating an OEC cluster pendant. The center stone is a 5.98-6.14 mm OEC that I already own. I have found two pieces with OEC stones that I would salvage for the project. One has 2mm stones and the other 3 mm. I am terrible at this kind of thing - can anyone tell me how many 2 mm stones I would need? How many 3 mm stones if I went that direction?