At First Glance,

I thought these fabulous glass globes were paper weights, 

 but they are not, they are pendants,

 fantastical miniature universes that can be worn, rather like the Orion's Belt that the cat was wearing in Men In Black 1,

 these miniature pieces of jewellery are the work of glass artist Satoshi Tomizu who sculpts small glass spheres that appear to contain entire solar systems and galaxies, the planets are made of opals and flecks of real gold, 

each sphere has a loop of glass to make it easy to wear, but if I had one I would be looking at it under a magnifying glass rather than wear it! to see more of his work have a look here.