Rough diamonds resemble broken glass and are translucent. One can see into them but not completely through them typically. Diamonds feel as if they have an oily film. They have a metallic luster without having a solid dull look.
The public can search for rough diamonds at the Crater of Diamonds state park in Arkansas. The average size of rough diamonds found in the park is roughly the size of a paper match head. A 1-carat diamond is about the size of a pea. Arkansas's Crater of Diamonds state park is the only place in the world where the public can search for diamonds and keep them for themselves.