I Tumbled Extremely Rare Agates скачать в хорошем качестве

I Tumbled Extremely Rare Agates

In today's batch of rocks I show off some of the amazing pieces of binghamite agates I tumbled. Binghamite is an extremely rare agate found in only one locality in the entire world; The Cuyuna Iron Range of central Minnesota. One of the unique qualities of this amazing rock is the beautiful chatoyancy it displays. This is caused by fibrous iron minerals that have been replaced by chalcedony. The light is reflected through these fibers and displays as a lighter band that runs perpendicular to the fibers. The various colors are caused by different iron minerals. These rocks were kind of a challenge to tumble for a few reasons. The first is that they were very fragile, and would often crack or fracture. They also sometimes had a tendency to undercut in certain places.