Crashed UFO pen holder with rainbow light emitting diode effect. CR2032 coin battery and switch in base. Cactus and highlights in glow-in-the-dark clay. Rest is made with Super Sculpy ®. Armature in cactus, pen "cave", saucer and to hold saucer to base.
Switch for lighting was baked into base (switch selected for size and temperature range). Other electronics were added after baking. Heat shrink tubing on LED leads to make them more attractive. Battery holder is hot-glued into base. LED just stays there on its own.
Rainbow LED slowly changes color, gently morphing between colors ranging from white when all elements on to deep blue, red or green. It is approximately a 3V diode, and the CR2032 is a 3V battery. Experiments with the LED indicate a resistor is not needed to limit current.