Star elf

Star elves, or mithral elves or Ruar-tel-quessir as they used to be known, like sun elves have only recently ventured back into Faerûnian life. Long ago they retreated to the demiplanar realm of Sildëyuir, where they are currently under attack by an extraplanar threat. As a result, some are now returning to the Yuirwood.

Physical characteristics
Star elves look a lot like moon elves, with light skin and hair of gold, red, or silver. They have violet or gray eyes with occasional gold flecks in them. They are tall for elves, being about 5 1/2 to 6 ft tall, and have a slender build. They like to wear elaborate tunics but in neutral tones, so as to better remain unseen in the forest. They are strikingly handsome by human standards, even more so than other elves.

Psychology
Aloof and cautious, star elves are unfamiliar with recent events in Faerûn and even other races. Isolated in the twilight realm of Sildëyuir, they had no contact with dwarves, gnomes, halflings, and even humans, and they liked it that way. It was the war-like and expansionistic humans that caused them to create the realm of Sildëyuir and flee their home in the first place. They generally get along with other elves, though they fear for the moon elves and half-elves of Aglarond who they believe are overly generous and a touch naive.

Perhaps not surprisingly, star elves as a race are generally chaotic in nature rather than lawful. They value individual accomplishment and rights over the demands of society.

History
In -6950 DR star elves began to gather in the Yuirwood, where a number of green elves already lived. Shortly thereafter the star and green elf nation of Yuireshanyaar was formed in -6600 DR. They had over 5000 years of peace during that time, largely isolated from the other events occurring across Faerûn. Around -1250 DR the human nation of Unther expanded to the southern coast of Aglarond and battled Yuireshanyaar. The elves lost, and retreat back into the woods. Less than 200 years later the elves were assaulted by orcs during the Orcgate Wars.

In -900 DR the elves begin to notice the rise of Narfell and Raumathar, and knowing that history repeats itself they foresaw disaster in the humans' misuse of magic. With the Untheric humans on their southern coast, orcs in the mountains due east, and two powerful and dangerous human nations to the north, the star elves decide that they needed to find a safer home. The elven high mages created a network of stone circles around the Yuirwood, which was then used to channel a spell that formed the demi-plane realm of Sildëyuir. Finally, in -699 DR the star elves completely abandoned Yuireshanyaar for Sildëyuir. Most of the green elves decided to remain behind.

The star elves of the Yuirwood retreated to this plane and have stayed there until recently, forced out by alien sorcerers called Nilshais who corrupt their home with strange magic.

Behind the scenes
In the source book Unapproachable East where we have the first illustrations of this race they are drawn with a small light source attached to their heads. This lightsource is never mentioned in the text, not even in the description of the star elves. Since it does not hover, but is attached to a headband they are wearing, one can only assume that it is a common item the star elves wear in their twilight realm of Sildëyuir.