Sansa necklace

Here's an attempt at Sansa's necklace bead from the the Darth Sansa scene in Game of Thrones season 4. It measures approximately 70mm across and 10mm tall, and is a little flatter on the bottom than the top so printing will be easier.

This would make an excellent tutorial object in 123D Design - create a cylinder with 35mm radius & 10mm height, create a cylinder with a 25mm radius, move the small one to overlap the big one, subtract the small one from the large, create a 10x10x50mm rectangle, merge, then fillet the edges.