Put a modern twist into your designs with the smoky quartz 8x10mm tumble nugget beads from Dakota Stones. Available by the strand, these gemstone beads feature a cube-like shape with rounded edges. They would look great in a contemporary bracelet design. Smoky quartz is named after its smoky color, which is caused by gamma rays. The color of smoky quartz ranges from brown to black and sometimes smoky gray. Mined in Brazil, the stone is believed to enhance organizational skills, making it good to have around the workplace or home office.