I think it MAY be
Tolkien plays on certain issues related to Gems now and again, and mankind's covetousness. As Sherlock Holmes says, the 'great gems' are always a matter of
evil. (my words there.)
But Tolkien shows us three different elements in 3 different peopls.
With the
Arkenstone of the
Dwarves, we see pride of 'ownership' coupled with covetousness generating sickness. (It belongs to the King so it's "mine", even at the expense of war and death to others.)
With
the Silmarils, we see pride of creation coupled with covetousness, (I made them, they belong to me, I will never be able to recreate them, they are "mine", even at the expense of light for all the
peoples.)
And with
Morgoth, we see pure evil covetousness. "I have no claim on them, but I want them and no one else should therefore have them."
(This is just a very brief statement of the nature of the covetousness at work.)
Covetousness is one of the "Moral and Religious Elements" Tolkien wrote into his works... and an excellent example of doing so 'subtly, not explicitely'.
He didn't 'say' it, as usual.
He 'demonstrated' it.
It will appear in my book.
Of course, we see covetousness at work in
the Ring as well, a very different sort of 'shiny object' in a way - and maybe not so different after all.