Seeing whatʼs inside is one of the enjoyable aspects of Rock or Gem collecting. There are a number of different ways this can be accomplished. Rocks and Gems can be cut and polished to expose the inner beauty. I have recently (2016) begun the enjoyable activity of rock tumbling. Iʼm fascinated and joyous over what I find in each rock. I tumble some Agate that is so rough on the outside that it needs extra time in the coarse stage to expose the extent of the beauty inside. I have left some of my more rugged Agate in stage one for as long as 3 weeks.
On the same note, be sure not to grind right through the awesome exterior patterns. Always carefully pull a few rocks out to examine before dumping and cleaning everything out. I found this out the hard way and ended up dumping my barrel, just to refill it with the same stage. When doing this, thereʼs no need to dump your barrel until complete, but be sure to add fresh grit once a week.
A diamond saw is a fast way to discover what is inside a rock. People often break geodes open by hitting them with a hammer, but itʼs much nicer to have two clean halves. With lapidary arbors and wheels, you can grind, sand and polish a small side, creating a sort of window into the interior. We recently discovered a pile of jet-black rock in our collection. We were close to using this rock in a retaining wall but decided to cut a piece open, only to discover that it was beautifully pink and black Rhodonite, and the black exterior was an ultra-thin layer of oxidization.