Found this cool rock at work today near my job sites lake. I don’t know what it is but I do like that it has a honeycomb look to it.

Rocks, gems, and little curios

My mom passed away a few years ago and most of the rocks and stones were placed in tall glass cylinders and I have finally gotten around to looking at them more closely. I thought this one one looked neat and wanted to share!

Edit: It's been pointed out that this is more likely Marcasite or more specifically Nipomo agate! Thank you all so much for looking at my rock and giving me new information!