As an experiment in extending 3D printing technology out to more traditional production techniques, I developed a composite stone stand for phones and small tablets. The project page includes all the details, including materials, resource files, process, and my failed experiments. I have also included a 30+ minute video of the casting and finishing process.
A limited number of these stands are available on Etsy. Or you can print yourself one in plastic using the 3D file on the project page.