Lots of projects use LEDs. Here we'll be modifying the LED itself to resemble a gem. Doing this also changes the light output pattern of the LED, throwing more light to the sides and less forward.
Step 1: The Inside of the LED / the Plan
The common LED has a die (the light emitting element) in a cup on one lead, and a fine wire from the other lead to the die, all enclosed in plastic. This plastic enclosure protects the sensitive electronic elements and focuses the light produced. So long as we don't get too close to the delicate parts inside we can safely reshape the lens.