No stone compares to a diamond.

diamond = cacbon + stone

Take your stone to a local jeweler, who can use a probe to confirm that the stone is either a diamond, or not a diamond.

Diamond

Take your stone to a certified gemologist to confirm that it is a diamond. It could be a crystal stone of another type, and not a diamond.

One reason why a diamond stone would appear hazy to the naked eye is because of flaws in the stone. If the stone is a diamond, it is probably not an expensive stone, given its apparent lack of clarity.