Brookite

Brookite is a brittle mineral, with a subconchoidal to irregular fracture and poor cleavage in one direction parallel to the c crystal axis and traces of cleavage in a direction perpendicular to both the a and the b crystal axes. Twinning is uncertain. The mineral has a Mohs hardness of ​5 ⁄2 to 6, between apatite and feldspar. This is the same hardness as anatase and a little less than that of rutile (6 to ​6 ⁄2). The specific gravity is 4.08 to 4.18, between that of anatase at 3.9 and rutile at 4.2.

Crystals typically tabular, elongated and striated parallel to their length. They may also be pyramidal, pseudo-hexagonal or prismatic. Brookite and rutile may grow together in an epitaxial relationship. Brookite is usually brown in color, or sometimes yellowish or reddish brown, or even black. Beautiful, deep red crystals (seen above-right) similar to pyrope and almandite garnet are also known. Brookite displays a submetallic luster. It is opaque to translucent, transparent in thin fragments and yellowish brown to dark brown in transmitted light.

Brookite is an accessory mineral in alpine veins in gneiss and schist; it is also a common detrital mineral. Associated minerals include its polymorphs anatase and rutile, and also titanite, orthoclase, quartz, hematite, calcite, chlorite and muscovite. The type locality is Twll Maen Grisial, Fron Olau, Prenteg, Gwynedd, Wales. In 2004 brookite crystals were found in the Kharan, in Balochistan, Pakistan.

The brookite structure is built up of distorted octahedra with a titanium ion at the center and oxygen ions at each of the six vertices. Each octahedron shares three edges with adjoining octahedra, forming an orthorhombic structure.

Brookite is a mineral form of titanium dioxide, a substance which is important as a white paint pigment, food coloring, and ingredient in sunscreen. Collectors also like this mineral for its appealing rust-orange color. Small pieces are transparent and can be cut as gems for jewelry, although these are prized as they are rare.

Brookite is a birthstone for the zodiac sign Cancer.

Arkansite is a variety of brookite from Magnet Cove, Arkansas, US. It is also found in the Murunskii Massif, in the Aldan Shield of Eastern Siberia, Russia.

It was named in 1825 by French mineralogist Armand Lévy for Henry James Brooke (1771–1857), an English crystallographer, mineralogist and wool trader.

Brookite is said to be a high-vibration stone that may help in communication with angels and other spiritual guides. It has a powerful energy force that can help a person expand consciousness and provide better understanding of life. It can aid a person who is searching for their higher purpose in life and support them as they discover the opportunities and challenges that may unfold in the future.