"Makes you wonder if a structural red could be created. I would guess not, otherwise it would exist in nature" Moonstone sometimes exhibits red-orange colorati

"Makes you wonder if a structural red could be created. I would guess not, otherwise it would exist in nature" Moonstone sometimes exhibits red-orange coloration due to its structure of alternating layers of different types of feldspar. Opals do the same thing but by water-filled fractures inside a group of quartz spheres. We can synthesize both so making a structural red should not be difficult.