This makes me curious, and I googled a bit trying to find how large you can grow these transparent, cubical crystals. Largest I was able to find was about 2cm

This makes me curious, and I googled a bit trying to find how large you can grow these transparent, cubical crystals. Largest I was able to find was about 2cm to a side, maybe a bit less.. Is there any fundamental reason they don't get bigger than this/lose transparency and form as they grow larger, or is it more that no-one bothered doing growing them larger than that?