Here's some pictures of beads from the Devardi Website under "Natasha's GlassArt". I don't see any cracks with the Devardi and Double Helix Glass combination.
Devardi Opaque Salmon, Transparent Orange, High Density Black, & Double Helix Aion 2 Silver rich glass.
Devardi Trans Purple base, with SOP Mango, encased with Precision Clear and Precision DaVinci 1 Silver rich glass.
Devardi Trans Purple base, with SOP Mango, encased with Precision Clear and Precision DaVinci 1 Silver rich glass.
There is a rather large display of beads from all kinds of artists on the Devardi website. Here is the link to the artist page:
http://www.devardiglass.com/glassartists.htm . The beads are made with Devardi glass and just a myriad of other glasses, including Silver. Hayley, if you're getting scumming, bubbles and cracking, you must be heating the snot out of the glass. If all else fails, read directions on the site. It's pretty clear.