>For those who want to build a truly authentic, old-school Crystal Radio (that is, without using a modern diode), you'll be needing a high purity Germanium Crystal. They are generally not all that easy to find, but we've got them.
These are ultra-pure (99.99999%) Germanium Crystals. We also include a small 5/16" diameter brass ring that the crystal fits in. The ring makes it much easier to make electrical connection to the crystal. The Germanium Crystal behaves exactly like a modern diode, and is placed in the radio circuit exactly where you would a diode.
Germanium Crystal: $35.00