Blu-V is a clear glass that fluoresces blue under a U.V. light source. Recommend to use an ultraviolet L.E.D. light with a 365Nm-395Nm range for the brightest blue glow. This is a stable glass and can be used in any type of flame.
The blue UV reactive color you have been searching for! Almost clear in the rod, with a little air, this glass glows a nice bright blue in UV light.
