Sedimentary rock, rock formed at or near the Earth’s surface by the accumulation and lithification of sediment (detrital rock) or by the precipitation from solution at normal surface temperatures (chemical rock).  Dissolved minerals in the ground water precipitate (crystallize) from water in the pore spaces forming mineral crusts on the sedimentary grains, gradually cementing the sediments, thus forming a rock. Calcite (calcium carbonate), silica, and hematite (red iron oxide) are the most common cementing agents. You may be familiar with calcite (or lime) encrustation on old plumbing fixtures, showerheads, and inside hot water heaters. Sedimentary rocks may be divided into three basic categories: 1) Clastic, 2) Biogenic, 3) Chemically precipitated. This information can be published in our peer reviewed journal with impact factors and are calculated using citations not only from research articles but also review articles (which tend to receive more citations), editorials, letters, meeting abstracts, short communications, and case reports. The inclusion of these publications provides the opportunity for editors and publishers to manipulate the ratio used to calculate the impact factor and try to increase their number rapidly. Impact factor plays a major role for the particular journal. Journal with higher impact factor is considered to be more important than other ones.