Active color gemstone display

For now see the "photonic steampunk" idea on the mechanooptical conversion (& optical effects) page.
Also fine tuning energy gap sizes may come in for active emission too.
See: Organometallic gemstone-like compound.

Related

• Passive color gemstone display
• Color emulation – here we want to create light of the right wavelength right away though (like in LEDs or lasers)
• Fun with spins