PEGASUS GLAM GLITTER is natural material called MICA, a substance that is very interesting indeed. By doing a GOOGLE search for MICA, you can see just how many different applications it has, one of which is its ability to withstand very high temperatures which makes it ideal for use as a decoration in lampworking and other hot glass applications....
The different types and grades of Mica are vast, many of which are simply not good enough for use as a decoration in lampworking. We are very proud to have finally sourced what we consider to be the highest quality Mica, in terms of both it's beauty and it's ability to sustain short periods directly in the flame, without losing its shine and lustre. Poor quality Mica will immediately change once touched directly by a flame and become chalky and opaque, not a desirable look in a bead...!
Another reason Mica is a great way of adding beautiful sparkle into glass is that it is completely compatible with all types of glass, including Soda Lime glass and also Borosilicate glass. It does not have any COE and therefore does not place any stress upon the glass, either when completely encased or on the surface of the glass. Any instances of beads cracking when using Mica will not be due to the Mica itself, rather it will most likely be simply a matter of temperature control and/or glass incompatability.
Because the Mica can withstand being in a direct flame, reheating a bead once covered in mica is possible, before encasing it with clear glass. The temptation to keep the mica away from the direct flame is an overwhelming one, we lampworkers naturally fear placing anything pretty in a direct flame...! However, not reheating a bead covered in mica can cause cracking issues to the bead once it has cooled. If the bead core hasn't been kept above a certain temperature when building up a bead, it is in danger of cracking.
Making sure a beads core is heated up after mica is added, is a very important step. By doing this, you will eliminate any chance of losing a precious bead later on due to it cracking. Of course I can't fix any cracking issues caused by glass incompatability, this is the stuff of nightmares for all lampworkers...!!! Experienced lampworkers have learned valuable lessons regarding this issue and know how to avoid it..!