Last night I read some articles about solid light, slowing down light and possibly completely trapping it inside crystals as well as light teleportation through quantum entanglement and I just wanted to say that if Feanor was the greatest scientist of the elves, then his silmarils are a plausible creation, which might not take as much effort as you may think.
Not going to try to explain how he could have done it on his own, but since a source of light is needed, it got me thinking about the number of silmarils and the number of lights he had available during the year of the trees. Therefore, I am pretty certain his silmarils were not all the same - I think he saturated one with the light of the Golden Tree, one with the Silver Tree and one with the mixture of their lights.
So they had different colour.
At least to me it seems like something he would do. Why make three otherwise - he could just make one, if he wanted only the light of the trees intermingling.
Not to mention, Feanorian lamps - same principle I think, just a different light was captured inside, most likely from a weaker, more mundane source, something easily accessible, and the crystals into which it was trapped were subpar to the ones he used for the silmarils. He might have even used some mined from the earth - simple silica crystals.
I reckon it took him more effort to prepare the purest, most brilliantly cut gemstones for his silmarils than to fill them with the light of the trees.
Those are my thoughts :D Now I’d like to see some real-life silmarils, but I’m afraid science is only going to use these techniques to make faster computers. Oh well, maybe it’s for the best :D