Gypsum Rosettes
By John Gresham
Ever wonder how sand roses are created.... do you even know what they are? These beautiful formations occur naturally through geological phenomenon. This beautiful sandstone creation is also known as the gypsum rosette. Gypsum rosettes can have many appearances, they can be light colored with great luster, dark colored with a foggy luster, and it can even be composed of sand!
Actually, a gypsum rosette is not a rose at all; it is a mineral which crystallizes in a unique rosette growth pattern. Gypsum Rosettes can be found all across the world. They form lightning fast in terms of geological time. They are created in tens to hundreds of years. A unique legend, originating from the Middle East, claims that for every one of these stones that are found, Allah will bless the person who found it with good luck.
There are many varieties: some look remarkably like a rose flower with its petals open, while others form into beautiful bladed spheres. Gypsum is an evaporite, which means its crystals form during the evaporation of water. The crystals are shaped like prisms or flat plates, and can grow up to 1 meter. Gypsum can appear as transparent crystals (selenite); fibrous, elongated crystals (satin spar); granular and compact masses (alabaster); and in rosette-shaped aggregates called desert roses. Some even form large clusters comprised of many small rosette crystals which are the color of sand and usually brown. In order for gypsum rosettes to form they must have an arid environment, a large source of calcium sulfate, and a seasonal fluctuation of water. In terms of geological time, gypsum rosettes form very rapidly in that they form in tens to hundreds of years. This would explain their abundance across the world.
In Saudi Arabia, sand roses are found in the flat brine-rich Sabkhas (desert areas) which are prevalent in the Eastern Providence. Water from the Gulf of Arabia, which is full of brine, seeps underground into the Sabkhas. The brine rich water chemically concentrates the calcium sulfate which then crystallizes into the mineral gypsum. As the water evaporates and deposits throughout the seasons, the gypsum crystals grow in the intergrain pore spaces trapping the surrounding loose sand. Thus the superb geological phenomenon creates these beautiful gypsum rosettes!
The United States also has a vast amount of rosettes. They differ greatly from the appearance of the sand roses in the Middle East. Gypsum rosettes commonly occur in the clay layer of the earth's crust. In the same geological phenomenon, gypsum forms in the clay as a result of rising and evaporating moisture while creating certain chemical concentrations. The water from rivers and streams floods sometimes, concentrating the calcium sulfate which is abundant in the soil. The calcium sulfate then crystallizes into the mineral gypsum.
Most gypsum is used in the building and agricultural industries. As a building material, it's used in plaster, wallboard, cement, and ceramic tiles. In agriculture, it's used as an amendment to neutralize alkaline soil. Some gypsum that is dense and fine-grained is called alabaster and can be carved.
Common around the world, gypsum is found primarily in sedimentary rock. In North America, crystals can be found in New York, Utah, and Oklahoma. In this region, gypsum is mined and processed in a major production plant, located in the aptly named Plaster City between Ocotillo and El Centro. The whole area is white with dust.
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