As you can see in the video below, creator Cass 3D Designs turned his old PC motherboard into a coaster, with its LGA 775 socket and Intel chip front and center.
When I retired my old PC from my student times, I cleaned it out and rebuilt it into the oh-so-beautiful Phanteks Evolv Shift 2, installed some old games on it that I used to play, and kept it on display in the living room. But not all old hardware still works, nor would everyone want to keep an entire PC around for nostalgia's sake.
After running across the parts of his first PC build in storage, rather than throwing them out, he wanted to turn it into a memento, inspired by a friend's project.
He used a Dremel to cut out a square of the motherboard, but the edges didn't end up looking so great. To cover these, he designed and 3D-printed a trim piece for around the motherboard to cover up the edges, and then hot-glued the two together.
After test-fitting, he then made a silicon mould to put the board and trim piece together and then poured Epoxy resin into it to create the final product.
Of course, by this point, only half the work was done. Anyone that's worked with Epoxy will know that to create a nice clear view into it, the top layer needs to be sanded down, sanded down, and sanded down... and then polished to a crystal clear finish.
All things considered, this is a nice project to occupy some time without costing a ton of money -- this coaster will certainly be a conversation starter when friends are allowed over again. The only thing missing is being able to power up the chip to heat the coffee. And perhaps some RGB bling, too.