Minerals, quite simply, are the building blocks for making rocks, and a rock is made up of one or more minerals. Among the over 3,000 named minerals, there are only around 30 minerals that non-geologists are interested in collecting. Mostly Gem hunters like us!

The four criteria to be met to be called a mineral–

• It is inorganic

• Naturally occurring (not man-made in a lab)

• It has a crystalline structure (a specific repeating pattern of atoms)

• It always has the same chemical makeup (Quartz=SiO2)

Brookite is one of the five forms of titanium dioxide found in nature. Named in honor of Henry J. Brooke, an English mineral expert, who discovered many new mineral species during his career. Formed as an accessory mineral in igneous rocks, and in sedimentary rocks caused by their weathering, this uncommonly yet widespread mineral occurs in alpine veins through gneiss and schist. It also forms in contact metamorphism zones, hydrothermal veinlets, and also as a detrital mineral. Brookite can be easily identified by its deep reddish brown color and morphology. Brookite crystals are typically found to be elongated, tabular, and striated parallel in length. They can also be pyramidal, prismatic or pseudo-hexagonal. Brookite is normally unearthed in Fronolen, North Wales, or the Alps. It can also be discovered in locales including the US, Austria, Norway, Russia, Italy, Brazil, France and Switzerland.

Some more facts–

• Formula: TiO2

• Crystal System: Orthorhombic

• Crystal Habit: Tabular, Platy

• Cleavage: Indistinct, None, None

• Luster: Submetallic

• Color: brown, light brown, dark brown, dark reddish brown, orange

• Streak: yellowish white

• Class: Orthorhombic – Dipyramidal

• Fracture: Sub Conchoidal

• Hardness: 5.5-6

The associated minerals include quartz, hematite, calcite, chlorite, anatase, rutile, titanite, orthoclase, and muscovite.  Learn more about minerals on our site and watch for our Mineral of the Month posts for more information!