One of the cooler gifts I received for Christmas, was this massive 7lb slice of quartz filled agate. I'm still unsure whether this qualifies as an agate or a solid geode. One side is really showy of the quartz interior. 
The other side shows more of the blue agate bands & the exterior layer. The shell formed in such a way that it was gooey enough for other rocks and bits to stick to it but not hot enough to melt them, even though the interior stayed hot enough, long enough, for the gasses to expand the inner cavity. It's a pretty exaggerated example of the strange conditions and dual pressures required for geode formation.

I heavily contemplated using it as a charcuterie board yesterday. I did not and decided it's probably prettier with a candle behind it.

But... rocks tell long stories (sometimes I do, too)... it never ends there. After breaking out the loupes and the lights, I decided it's probably the most beautiful under long wave UV.

I spent some time researching and consulting about it this morning. I'm fairly confident the glowy green streaks and spots are rhodocrocite inclusions. My homework is now to figure out what trace minerals are providing the dominant hot pink fluorescence around the quartz.
especially with the candle behind it