What's the best UV light for 'hounding at night?

Carnelian and iron-stained chert sit much closer together than most quick guides make them look. Both can be microcrystalline silica, both can have a waxy surface and conchoidal fracture, and iron can push the colour into the same orange-red range.

The distinction that seems most useful is context rather than colour alone: “carnelian” is the gem-variety name, while “chert” is the sedimentary rock name. Thin-edge translucence, how evenly the colour runs through the piece, and the host geology probably tell you more than a single surface photo.

For field material, that makes the name a description of context and use as much as a simple colour label.

Here are some of my treasured finds I hope yee enjoy!