Topic: some of my newest additions to my family of Monart

[Lustrousstone]

I think you mean uranium for glowing under UV

[chopin-liszt]

We were talking about the stuff that glows but not as much as uranium, the manganese.

Yes, Roberta, it's the manganese that turns purple in sun-purpled glass.

[KevinH]

A "green glow" under longwave uv light in Monart glass (pre- and post-war) and also in Ysart Brothers glass (1946-1955) is normally due to the manganese. It can usually only be seen in the clear glass.

In my experience (mostly with paperweights) the shade of the "green glow" can vary from a "yellow green" to a "not so bright regular green". Some of the "earlier" millefiori canes with a substantial amount of clear glass (such as when used as the central core) can show up as a seemingly "very bright yellow green" which some folk claim is an indicator of uranium. Whether that is the case or not well beyond my knowledge.