Barite is well-known for its great range of colors and varied crystal forms and habits. It is an immensely popular mineral among collectors. Barite is easily identifiable by its heavy weight, since most similar minerals are much lighter. Barite often replaces other minerals, and may even replace organic materials such as wood, shells, and fossils. It sometimes forms tufacious mounds from deposition of hot, barium-rich springs. Barite specimens from certain locations are brown from sand inclusions, and may occur in beautiful rosette aggregates that strikingly resemble a flower. These are known as Barite "Desert Roses". The mineral Gypsum also contains similar Desert Roses, but the Gypsum roses are much light in weight, and are more brittle and thin. Barite is isomorphous and very similar in form with the mineral Celestine, and may partially replace it.