â¢ SULTAN (noun). The noun SULTAN has 1 sense: 1. the ruler of a Muslim country (especially of the former Ottoman Empire). Familiarity information: SULTAN used as a noun is very rare. SULTAN (noun). The noun SULTAN has 1 sense: 1. the ruler of a Muslim country (especially of the former Ottoman Empire). Familiarity information: SULTAN used as a noun is very rare.
Fossils also form from molds and casts. If an organism completely dissolves in sedimentary rock, it can leave an impression of its exterior in the rock, called an external mold. If that mold gets filled with other minerals, it becomes a cast. An internal mold forms when sediments or minerals fill the internal cavity, such as a shell or skull, of an organism, and the remains dissolve. Organic remnants. In recent years, researchers have discovered that some fossils aren't just made of minerals.
A rock known as tufa is a limestone formed by evaporation at a hot spring, lake shore, or other area. Limestone is by definition a rock that contains at least 50% calcium carbonate in the form of calcite by weight. All limestones contain at least a few percent other materials.These can be small particles of quartz, feldspar, clay minerals, pyrite, siderite and other minerals.t most commonly forms in clear, warm, shallow marine waters. It is usually an organic sedimentary rock that forms from the accumulation of shell, coral, algal and fecal debris. It can also be a chemical sedimentary rock formed by the precipitation of calcium carbonate from lake or ocean water.