Moving sand pictures. The double-strength glass is framed with a quality knotty alder wood frame. The black sand is heavier than the white sand so the two will never mix, some of the sands are transparent and some opaque giving the pictures a cool 3-d effect. Pictures may take from minutes to several hours to finish a magical landscape, tiny air bubbles hold up the sand creating unique natural scenes with every turn. Choosing the perfect gift for any occasion can be a delightful experience when you consider the recipient’s personality and interests. Exotic Sands make for a unique and thoughtful gift, capturing the beauty of shifting sands in a mesmerizing display. Whether you’re shopping for Christmas, birthdays, or any holiday, this artistic piece can be a perfect choice. Its ever-changing patterns can bring a sense of tranquility and wonder to any space, making it a memorable and cherished gift. Sizes: 7" x 9", 7" x 12", 9 " x 12", 9" x 16.