Circle Cut Diamond

This is a circle cut diamond. I modeled it using proper diamond-cutting techniques. I researched the techniques for a few days, they are quite interesting and intricate. Modelling it was fairly difficult. It took me 3 attempts and I had to set up many reference planes. At first I thought I could do it completely mathematically, but slowly resorted to "edit-and-perceive" techniques towards the end of the modelling process. I used Autodesk's Fusion 360 to model it and to make the STL, then MakerWare to create the OBJ and THING files.

There are two STL filetypes available: ASCII and Binary. They are labeled as such in the filename.

I've included a few renderings I've done of the diamond. Renderings were done in Fusion 360 as well. I couldn't get Fusion to do a red refraction to give the diamond what is known as a "fiery" appearance. I believe I got the angles within 2% of what would be considered an ideal cut, so using the correct lighting and textures (within software such as 3DS