Calcedonia Tube Twisted 20mm

These are very unusual tubes with a twist, they have the of the very unpredictable Calcedonia glass made popular by Dino Rosin sculptures. They are encased exterior in crystal. Each one unique - exact placement of design and the colors vary by bead as you can see from the beads in the picture. The tube is approximately 20mm in length and about 15mm in diameter. This is the case of the glass being named after the stone. The colors of Calcedonia glass,resemble the stripes in a zoned agate, These unpredictable colors are created through the introduction of silver nitrate to crystal clear glass. The colors cannot be controlled since the colors depend solely upon the chemical reaction of each batch.