SciShow Rocks Box: Desert Rose

Chemical Formula: BaSO4 Location: Samalayuca Desert in Chihuahua, Mexico Mohs Hardness Scale: 3-3.5 What you’re looking at is not a fossilized flower, though you’d be forgiven for thinking that. This is a desert rose, a crystal concretion formed when petals of gypsum or barite grow in thin sheets, studded with tiny shards of quartz. Desert roses are known to occur in two main locations: Oklahoma, where they formed over the span of millions of years, and Qatar, where they grow in just decades. In Oklahoma, the water that made their petals possible rose up from deeper underground, carrying with it the building blocks for desert rose formation. The water evaporated slowly, allowing these thin sheets of barite to grow over millions of years. But in Qatar, desert rose growth is on fast-forward. The constant evaporation of water from the sandy desert coupled with perpetual influx of seawater is all you need to get beautiful desert roses in just a few years.