Coppery Aqua Sisters: Sky Blue (SP SF533.1), Blue Topaz (SP SF533.2) and Deep Aqua (SP SF533.3) All three of these blues contain copper, they create lovely, delicate reactions when fused next to glasses formulated with Sulfur. These transparent blues also work great with System 96 Red Reactive glasses.
For a great tutorial featuring this Blue Topaz glass interacting with shades of sulfur-containing Ambers in Patty Gray's Dam Mold (FUS GM110), click here.