Posted to their blog in late December 2011, the Crystal Stickers appear to be releated to Muse's 2012 book fair. No exact release date is known, however.
They retail at a regular 99元 each, but cost only 89元 if preordered.
No second hand value is known.
Each sticker is 44mm x 44mm. They feature chibi art of a character in the bottom right corner, while the background is their flag, covered in small crystals, likely plastic.
The characters these stickers have been made for are Italy, Germany, Japan, America, England, France, Russia and China.