|See this brand new product listed in the online shop under 'Lumiere Lusters" by JetAge Studio are specialty color shifting, heat resistant metal oxide powders and flakes and powders that work glittery magic in lampworked glass, and a multitude of other mediums. They are rated to resist heat up to about 1400F, and don't have a specific coefficent. Similar to Dichroic Extract powder, they shift color and throw off a lot of shine. The larger particle sizes create a lot of sparkle that you cant get from micas, and give quite a different effect from powdered extract. They're also a great cost effective alternative to dichroic coatings and are more heat tolerant than regular powdered micas.