3cm - 4cm Smoky Quartz is found in the veins of igneous and metamorphic rocks. Well-formed smoky quartz is found in the cavities of metamorphic rocks. This mineral's color varies depending on where it is found. In areas where there are radioactive mineral deposits, Smoky Quartz is very dark due to the emissions. Brazil and Madagascar are the world's biggest suppliers of Smoky Quartz. ***Due to natural variations of stones, the appearance will vary***