The graphite space can be tough for investors to navigate. Getting a grasp on it involves knowing a little about the different types of graphite.

Graphite has a layered, planar structure, with carbon atoms arranged in a honeycomb lattice. It’s because of this unique structure that graphite has such a stellar combination of properties — for example, it’s flexible, highly refractory, chemically alert and has high thermal and electrical conductivity.

Those characteristics allow graphite to be used in a variety of places, including brake linings, foundry operations, lubricants, refractory applications and steelmaking. However, not all graphite is suitable for all applications. Indeed, there are three main types of graphite, and in many cases specific applications require one type in particular.

Here’s a brief look at those three types of graphite and how they’re used in the world today.

Flake graphite

Flake graphite occurs as isolated, flat, plate-like particles with either hexagonal or angular edges. It is found in metamorphic rocks — such as limestone, gneiss and schist — either uniformly distributed through the body of the ore or in concentrated, lens-shaped pockets.

Amorphous graphiteAmorphous graphite is found as extremely small, crystal-like particles in beds of mesomorphic rocks like coal, slate and shale, and its carbon content depends on that of its parent material. When found in coal it is the result of the thermal metamorphism of coal, and is referred to as meta-anthracite. However, unlike coal, amorphous graphite is not used as fuel as it is difficult to ignite.

Vein graphiteVein graphite, also referred to as lump graphite, is believed to have hydrothermal origins and occurs in fissures or fractures, appearing as massive platy intergrowths of fibrous or needle-like crystalline aggregates. Vein graphite is believed to originate from crude oil deposits that through time, temperature and pressure were converted to graphite. Riddle said that the veins “are extremely small and range between 5 and 10 centimeters wide;” generally they have a purity level of 70 to 99+.

UsesVein graphite is used in advanced, thermal and high-friction applications such as car brakes and clutches. It can also be used in much the same way as flake graphite as its shows great performance in applications that require high thermal and electrical conductivity.