MARK RICHARDS-Crystal Stickers: Elements. These stickers are acid free and adhere to virtually any surface. Crystal Elements offers gem stickers in various sizes The assortment stickers include sizes 3mm, 4mm, 5mm and 6mm. These stickers also are available in a variety of shapes, words, designs, alphabets and fashionable colors. Size, color, shape and number of stickers vary by package. Imported.