This chalcedony and Scottish quartz crystal for sale probably fits into the agate category, but I am erring on the side of caution. It was collected back in 2021 and has only just come out of the tumbler. It's had four stages and a soap stage. The chalcedony parts have this intense shine while the quartz parts remain duller. 
This is a geode, meaning it was hollow when cut. The quartz has a purple hue to it, enough that you could call it pale amethyst. There are lines of chalcedony all around it, but again, I'm not confident to call it agate. That purple tinge coupled with the geode feature makes this piece special.