Grossite is a calcium aluminium oxide mineral

Oxide mineral

The oxide mineral class includes those minerals in which the oxide anion is bonded to one or more metal ions. The hydroxide bearing minerals are typically included in the oxide class...

 with formula CaAl₄O₇. It is a colorless to white vitreous mineral which crystallizes in the monoclinic crystal system

Crystal system

In crystallography, the terms crystal system, crystal family, and lattice system each refer to one of several classes of space groups, lattices, point groups, or crystals...

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Grossite was first described 1994 for an occurrence in the Hatrurim Formation

Hatrurim Formation

The Hatrurim Formation or mottled zone is a geologic formation in the Negev Desert in Israel and in western Jordan. It includes late Cretaceous to Eocene aged impure limestone along with coal bearing chalk and marl. The rocks have been subjected to pyrometamorphism resulting from combustion of...

 of Israel

Israel

The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

. It was named for Shulamit Gross (1923- ) of the Geological Survey of Israel.

It occurs within high temperature metamorphosed

Metamorphism

Metamorphism is the solid-state recrystallization of pre-existing rocks due to changes in physical and chemical conditions, primarily heat, pressure, and the introduction of chemically active fluids. Mineralogical, chemical and crystallographic changes can occur during this process...

 impure limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 of the Hatrurim Formation and also within calcium-aluminium rich inclusions in chondritic meteorite

Chondrite

Chondrites are stony meteorites that have not been modified due to melting or differentiation of the parent body. They formed when various types of dust and small grains that were present in the early solar system accreted to form primitive asteroids...

s. Associated minerals in the Hatrurium include brownmillerite

Brownmillerite

Brownmillerite is a mineral with an interesting structure. Its chemical formula is Ca22O5. It is named for Lorrin Thomas Brownmiller , chief chemist of the Alpha Portland Cement Company, Easton, Pennsylvania....

, mayenite

Mayenite

Mayenite , Ca12Al14O33, is a rare cubic mineral of cubic symmetry, originally reported from Eifel volcanic complex . It is also found at pyrometamorphic sites: e.g., in the Hatrurim Formation and in some burned coal dumps. The formula can be written as [Ca12Al14O32]O, which refers to the unique...

 and larnite

Larnite

Larnite is a mineral, known as dicalcisum silicate.Dicalcium silicate is chemically, β–Ca2SiO4, sometimes represented by the formula 2CaO·SiO2.When used in the cement industry, the mineral is usually referred to as Belite....

. In meteorites it occurs with perovskite

Perovskite

A perovskite structure is any material with the same type of crystal structure as calcium titanium oxide , known as the perovskite structure, or XIIA2+VIB4+X2−3 with the oxygen in the face centers. Perovskites take their name from this compound, which was first discovered in the Ural mountains of...

, melilite

Melilite

Melilite refers to a mineral of the melilite group. Minerals of the group are solid solutions of several endmembers, the most important of which are gehlenite and åkermanite. A generalized formula for common melilite is 2[SiO7]. Discovered in 1793 near Rome, it has a yellowish, greenish brown color...

, hibonite

Hibonite

Hibonite is a brownish black mineral with a hardness of 7.5-8.0 and a hexagonal crystal structure. It is rare, but is found in high-grade metamorphic rocks on Madagascar. Some presolar grains in primitive meteorites consist of hibonite. Hibonite also is a common mineral in the Ca-Al-rich...

, spinel

Spinel

Spinel is the magnesium aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4. Balas ruby is an old name for a rose-tinted variety.-Spinel group:...

 and calcium rich pyroxene

Pyroxene

The pyroxenes are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. They share a common structure consisting of single chains of silica tetrahedra and they crystallize in the monoclinic and orthorhombic systems...

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