Moderock CPU Wafer Silicon Art, Double Side Polished Uncut IC Si Wafer, Integrated Circuit Real Chip, Can Be Used As A Geek Toy, Gift, Viewing, Collection, Exhibition, Decoration Or Teaching, 5 in

I used this to check the focus on my macro lenses. Worked great for this porpose.

It arrived broken in about 4 or 5 large-ish pieces. Was not happy with this. I wanted one piece to use as a picture.

I wish I knew enough to identify what these were intended for. Still a very cool bit of tech art.

The Moderock Silicon Wafer is essentially industrial waste. That said, it's INTERESTING industrial waste! 4 and 5 inch wafers are pretty old, as is the extremely large-feature lithography. That makes the IC structure visible under magnification, but makes the wafer quite a bit less colorful than small-feature processes (like 250nm). I'm guessing these are using 3 µm lithography. My wafer arrived without any visual or structural imperfections.I guess the main thing would be: what do you want this for? If you're looking for a technology demonstrator, this is a decent piece. If you're looking for a piece of art, you're better off looking on an online auction site - as there are much more attractive wafers out there.