GTG Dark Matter

The size of each rod is approximatively 12 millimeters diameter for 10 centimeters long. 

The "Dark Matter" rods need to be preheated in a kiln or above the flame carefully before use them. 
 
These rods will be perfectly compatible with all the borosilicate creations that you will create. Just be careful to preheat them carefully  and maintain your piece enough hot during your work.
 

Work it with an oxidising flame in order to keep the black color intense and opaque, avoid neutral flames.
 

Use it "PURE" without mixing it with clear glass is also the best ways to keep a dense black onyx color. Oxygen tanks are recommended (pressure). 
 

Maintain the proper heat base while working, and when finished, put it into the kiln at the proper annealing temperature (1080°F) . 
 

Wait until your kiln has dropped to a temperature of 302°F before opening the door, and you can remove your piece when it has reached room temperature.