Why did Fëanor refuse to give even one of the Silmarils to <PERSON> to revive the trees?
Right near the beginning Of the Flight of the Noldor:
<PERSON> spoke before the Valar, saying: "The Light of the Trees has passed away, and lives now only in the Silmarils of Fëanor. Foresighted was he! Even for those who are mightiest under <PERSON> there is some work that they may accomplish once, and once only. <PERSON> I brought into being, and within Eä I can do so never again. Yet had I but a little of that light I could recall life to the Trees, ere their roots decay; and then our hurt should be healed, and the malice of <PERSON> be confounded.'
<PERSON> needed "but a little of that light" to revive <PERSON> and <PERSON>, yet <PERSON> refused to give the <PERSON> up:
Then <PERSON> spoke and said: 'Hearest thou, <PERSON> son of <PERSON>, the words of <PERSON>? Wilt thou grant what she would ask?' There was long silence, but <PERSON> answered no word. Then <PERSON> cried: 'Speak, O <PERSON>, yea or nay! But who shall deny <PERSON>? And did not the light of the Silmarils come from her work in the beginning?' But <PERSON> the Maker said: 'Be not hasty! We ask a greater thing than thou knowest. 381
Let him have peace yet awhile.' But <PERSON> spoke then, and cried bitterly: 'For the less even as for the greater there is some deed that he may accomplish but once only; and in that deed his heart shall rest. It may be that I can unlock my jewels, but never again shall I make their like; and if I must break them, I shall break my heart, and I shall be slain; first of all the Eldar in <PERSON>.' 'Not the first,' said <PERSON>, but they did not understand his word; and again there was silence, while <PERSON> brooded in the dark. It seemed to him that he was beset in a ring of enemies, and the words of <PERSON> returned to him, saying that the Silmarils were not safe, if the Valar would possess them. 'And is he not <PERSON> as are they,' said his thought, 'and does he not understand their hearts? Yea, a thief shall reveal thieves!' Then he cried aloud: 'This thing I will not do of free will. But if the Valar will constrain me, then shall I know indeed that <PERSON> is of their kindred.' Then <PERSON> said: 'Thou hast spoken.'
<PERSON> had three Silmarils. Why wouldn't he give just one?
* Was the real reason the mistrust <PERSON> helped engender?
* Was each one so dear that he was not willing to give any of them up?
* Was there too little light in just one? (But how would <PERSON> know that?)
* Were the three (thought to be) linked? 381