Mineralogy and Chemistry of Desert Roses, Ayn Dar Area, Abqaiq, Eastern Province, Saudi Arabia

Abstract

Desert roses are crystals which usually take the form of rose petal. They have definite crystal shapes, and enclose sand grains. The desert roses were scattered along an area of about 500m2 in the Ayn Dar area, near Abqaiq, about 80km southwest of Ad Dammam, Eastern Province, Saudi Arabia. They are made up of gypsum crystals included sand grains in the from of rosettes, with distinctive petal morphology. Most quartz grains are cemented by gypsum crystals which show a fibrous structure. The main components of desert roses of Ayn Dar area are SiO^, CaO and SOy Other oxides include Na^O, K^O and small amounts ofFe, Al, Ti, Mg, Mn, Cr, Ni and P. High porosity and permeability in the Ayn Dar area permitted rapid ionic migration to promote the growth of desert roses. Desert roses crystals were grown in loose sand near the surface of the sabkha, and finally concentrated inside the sand as scattered large rose crystals. The large size of most crystals and the poikilitic inclusion of sand suggest accretion under stable hydrochemical conditions.