AFm phasesAn AFm phase is an "alumina, ferric oxide, monosubstituted" phase, or aluminate ferrite monosubstituted, or Al2O3, Fe2O3 mono, in cement chemist notation (CCN). AFm phases are important hydration products in the hydration of Portland cements and hydraulic cements.
Portland cementPortland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in the early 19th century by Joseph Aspdin, and is usually made from limestone.
ThaumasiteThaumasite is a calcium silicate mineral, containing Si atoms in unusual octahedral configuration, with chemical formula Ca3Si(OH)6(CO3)(SO4)·12H2O, also sometimes more simply written as CaSiO3·CaCO3·CaSO4·15H2O. It occurs as colorless to white prismatic hexagonal crystals, typically as acicular radiating groups. It also occurs as fibrous masses. Its Mohs hardness is 3.5 and it has a specific gravity of 1.88 to 1.90.
GypsumGypsum is a soft sulfate mineral composed of calcium sulfatedihydrate, with the chemical formulaCaSO4·2H2O. It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk chalk. Gypsum also crystallizes as translucent crystals of selenite. It forms as an evaporite mineral and as a hydration product of anhydrite.
Hexagonal crystal familyIn crystallography, the hexagonal crystal family is one of the six crystal families; it includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crystal system and the rhombohedral lattice system are not equivalent (see section crystal systems below). In particular, there are crystals that have trigonal symmetry but belong to the hexagonal lattice (such as α-quartz).AFt phasesAFt Phases refer to the calcium Aluminate Ferrite trisubstituted, or calcium aluminate trisubstituted, phases present in hydrated (or hardened) cement paste (HCP) in concrete.
Sulfate mineralThe sulfate minerals are a class of minerals that include the sulfate ion (SO2−4) within their structure. The sulfate minerals occur commonly in primary evaporite depositional environments, as gangue minerals in hydrothermal veins and as secondary minerals in the oxidizing zone of sulfide mineral deposits. The chromate and manganate minerals have a similar structure and are often included with the sulfates in mineral classification systems.
Crystal systemIn crystallography, a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point). A lattice system is a set of Bravais lattices (an infinite array of discrete points). Space groups (symmetry groups of a configuration in space) are classified into crystal systems according to their point groups, and into lattice systems according to their Bravais lattices.Scawt Hill
BentoriteBentorite is a mineral with the chemical formulaCa6(Cr,Al)2(SO4)3(OH)12·26H2O. It is colored violet to light violet. Its crystals are hexagonal to dihexagonal dipyramidal. It is transparent and has vitreous luster. It has perfect cleavage. Bentorite is rated 2 on the Mohs scale. The mineral was first described in 1980 by Shulamit Gross for an occurrence in the Hatrurim Formation of Danian age along the western margin of the Dead Sea, Israel.
CalciumChemical element with atomic number 20 (Ca)Mg↑Ca↓Srpotassium ← calcium → scandium
AluminiumChemical element with atomic number 13 (Al)B↑Al↓Gamagnesium ← aluminium → silicon
Portland cementPortland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in the early 19th century by Joseph Aspdin, and is usually made from limestone.ThaumasiteThaumasite is a calcium silicate mineral, containing Si atoms in unusual octahedral configuration, with chemical formula Ca3Si(OH)6(CO3)(SO4)·12H2O, also sometimes more simply written as CaSiO3·CaCO3·CaSO4·15H2O. It occurs as colorless to white prismatic hexagonal crystals, typically as acicular radiating groups. It also occurs as fibrous masses. Its Mohs hardness is 3.5 and it has a specific gravity of 1.88 to 1.90.GypsumGypsum is a soft sulfate mineral composed of calcium sulfatedihydrate, with the chemical formulaCaSO4·2H2O. It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk chalk. Gypsum also crystallizes as translucent crystals of selenite. It forms as an evaporite mineral and as a hydration product of anhydrite.Hexagonal crystal familyIn crystallography, the hexagonal crystal family is one of the six crystal families; it includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crystal system and the rhombohedral lattice system are not equivalent (see section crystal systems below). In particular, there are crystals that have trigonal symmetry but belong to the hexagonal lattice (such as α-quartz).AFt phasesAFt Phases refer to the calcium Aluminate Ferrite trisubstituted, or calcium aluminate trisubstituted, phases present in hydrated (or hardened) cement paste (HCP) in concrete.Sulfate mineralThe sulfate minerals are a class of minerals that include the sulfate ion (SO2−4) within their structure. The sulfate minerals occur commonly in primary evaporite depositional environments, as gangue minerals in hydrothermal veins and as secondary minerals in the oxidizing zone of sulfide mineral deposits. The chromate and manganate minerals have a similar structure and are often included with the sulfates in mineral classification systems.Crystal systemIn crystallography, a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point). A lattice system is a set of Bravais lattices (an infinite array of discrete points). Space groups (symmetry groups of a configuration in space) are classified into crystal systems according to their point groups, and into lattice systems according to their Bravais lattices.Scawt HillBentoriteBentorite is a mineral with the chemical formulaCa6(Cr,Al)2(SO4)3(OH)12·26H2O. It is colored violet to light violet. Its crystals are hexagonal to dihexagonal dipyramidal. It is transparent and has vitreous luster. It has perfect cleavage. Bentorite is rated 2 on the Mohs scale. The mineral was first described in 1980 by Shulamit Gross for an occurrence in the Hatrurim Formation of Danian age along the western margin of the Dead Sea, Israel.CalciumChemical element with atomic number 20 (Ca)Mg↑Ca↓Srpotassium ← calcium → scandiumAluminiumChemical element with atomic number 13 (Al)B↑Al↓Gamagnesium ← aluminium → silicon*As an Amazon Associate I earn from qualifying purchases.