Two: Part I

The idea of the djinn pre-dates Islam, but that is where most of the source material available comes from right now. God created angels and djinn (presumably at about the same time), with angels going to heaven, and djinn going to earth. The explanation in the Qur'an is that one angel later rebelled, and was turned into a djinn, becoming one of the problem ring leaders of his new group. No explanation is given on how it was physically possible, nor is it explained how an angel (which in Islam do not have free will, unlike the djinn), managed to rebel. 

Muhammad said that was how it was, and no questioned it. Then again, Muhammad thought he was inspired by a djinn, not God, and it was his family and friends that convinced him otherwise, struggling for power control after he died. It was in their best interest not to question the man, however much his ideas might run contradictory to one another. 

I've looked at images of Mt. Hermon, which is currently best known for its skiing, while I remember a place that is sandy and arid, with not much vegetation except on the fringes. There were sandy pillars covered in writing, and the whole thing was on a platform that balanced itself (not unlike the one that shows up in the second National Treasure movie). From that platform, we could see the world below, but it took going down to humans for us to interact and we were often disinclined to do so. I've scoured over images of alphabets and languages as well, with what I remember being somewhere between cuneiform and extremely basic heiroglyphics.
Last, but not least, my memories oh my own physicality don't match up with those of the others here. I don't recall having six wings, just two, and I distinctly recall being a large feline around humanoids that were closer to what we'd consider Nephilim than Seraphim. The djinn are one of only three groups said to take on that kind of feline, winged form. 

Now, the only other human life I recall having, that man could easily have passed for an angel taking on a human form. He had long red hair, was tall (about 6' 4"), muscled, very pale (redhead, you know), but he had the same eye color I do (amber). He was a soldier, but I sometimes suspect my memories of the actual war were just the present-me placing him in a context I understand (the American Revolution).