I have researched all over the land and have finally come across some ancient documents that have led me to believe that there is a definite connection between the Crystals of my past world and the Silmarils of this world.
The following are direct copies, word for word, of some excerpts from the scrolls detailing the similarities between these elemental wonders.
"The Silmarils or Silmarilli, also called the Jewels of Fëanor, were the gems crafted by Fëanor from some essence of the Two Trees of Valinor; Laurelin and Telperion, in the First Age. They were among the most prized of all the wonders crafted by the elves and were coveted by many. It was said that the fate of Arda was woven about the Silmarils.".
Fëanor created the Silmarils during the Years of the Trees in the Noontide of Valinor. They were named for and crafted of the hard crystalline substance silima, and contained some of the light from the Two Trees of Valinor made by Yavanna and Nienna named Telperion the Silver, and Laurelin the Gold. Recognizing their immense beauty, they were hallowed by Varda, Queen of Arda so that no mortal flesh, hands unclean, or anything evil could touch them.
"One of the Silmarils was recovered by Beren and Lúthien through great peril and loss. This stone was later taken by Eärendil to the Valar in the West as a token of repentance. The Valar then set this Silmaril as a star. The other two gems remained in Morgoth's hands, and were taken from him only at the end of the War of Wrath. However, soon afterwards, they were stolen by Fëanor's two sons Maedhros and Maglor. The jewels burned their hands, in refusal of their rights of possession, as they had burned Morgoth's hands many years before. In agony, Maedhros threw himself and his Silmaril into a fiery pit, and Maglor threw his into the sea. Thus, the Silmarils remained in all three realms of Arda — in the sky, beneath the earth, and within the sea"
After I had read this I have deduced that if these "Silmarils" are indeed the same as our "Crystals", then the fate of the four crystals is as follows.
Air- The first element as space itself was needed to construct all matter. Being that the Valar, Earendil, made it a star, then this is the Air Crystal.
Fire- The second element being that the fire of the sun was needed to create the life on most worlds as it was needed to create the last two elements. Maedhros had fllung himself into a fiery pit and so this became the Fire Crystal.
Earth- The third element as the cooling of the fire is what constructed this material in the first place and it seems that this is either the same crystal as fire or something is missing as I can only find writing on three crystals. My idea is that stars are truly other planets and so this educated guess would mean that the Air Crystal of Earendil was not Air, but in fact the Earth Crystal. Which makes sense considering I have an Air Crystal myself which would allow this world to have four rather than three.
Water- The fourth element as it was created by the cooling of the earth and fire to make moisture from the condensing of those elements along with the additional cycle created by air. Maglor has thrown his into the sea and this makes this last one the Water Crystal.
Where I am confused is that there was only three realms of Arda — "in the sky, beneath the earth, and within the sea" Fire is missing however it was known to me from before that fire was also the one element that defied the rest in the lessons of my ancestors as well as the teachings of my masters. If that is true then this idea relates to the same defiance that Melkor, now named Morgoth by Fëanor, had shown to his brethren and I believe that this is the missing Crystal as well as the clue to a fourth realm. If this is true then I believe my journey shall begin with the Water and Earth Crystals, or Silmarils, and then to compare my Air Crystal to that of the star. My last journey shall lead me to the home of Melkor in search of the Fire Crystal. My element is also Air and I know that the opposite of Air, is Fire.
