The Subanite Brotherhood are a sacred order of monks that have exclusive rights on the mining, refinement, and supply of natural Subanese crystals. Although they concentrate their operations on their namesake body, they also have smaller holdings across the Covenant Sphere.

Tracing their roots to the original penal colonies that were established on Suban, the Subanite Brotherhood are mysterious and isolationist by nature. They primarily recruit individuals hailing from the nobility of Sangheili society, yet those who are considered respectable or determined enough may find a place in their ranks. This has led to the organization being considered an honorable form of exile, where they take in excess scions, or offspring with debilitating deformities or mental defects for whom conventional punishment would prove politically inconvenient. They are led by a single elder called the First Guardian of the Pink Mist, who directs all operations conducted by the Brotherhood.

Many of the methods used to mine and grow the crystals are jealously guarded in the order's archives, with only the First Guardian of Pink Mist and his apprentice knowing the exact mixture of raw materials necessary to produce Blamite of the highest quality, as well as how to read and maintain the Forerunner machine that grows them. As a result, they are the only organization that has the tools and procedures necessary to mine the natural crystals safely. However, commercial guilds may purchase an expensive license to fabricate less volatile and pure alternatives, although the Brotherhood retains strict control. For example, they are the sole producers of the Covenant vein-forges necessary for growing them, and enforce a policy that only allows their technicians to service, repair, and modify the devices. Any after-market resale must be authorized by the Brotherhood, with the order reserving the right to forcibly reclaim them at any time. The Brotherhood has a reputation for ruthlessly devoting itself to shutting down any non-vetted sources of crystals, with uncounted numbers of black-market operations ending under a hail of weaponized Subanite.

All senior members suffer from subosis, a disease which sees the crystals become deposited throughout their body. This gives the average monk a life-long of 40 - 50 years, with those being inducted later leading somewhat long lives. While this alienates them in the eyes of their species, it is championed by those within the Brotherhood, as it is a symbol of their devotion. Unexpectedly acute symptoms are also greatly respected, even if it brings with it terrible health issues later in life.