Fuel Gel

"Harvester of Nectar – Vyyth: When the oceanic waters receded from the primordial island, and land spread outwards in all direction, Vyyth poured upon the naked crust of the land the invigorating and restorative burning nectar. This immaculate serum has the powers to heal the sick and diseased. All newborn younglings are ceremonially bathed in this curative substance to ensure strong vitality." -Bryonnian description of Fuel Gel

Fuel Gel is the liquid in Metroid Prime 3: Corruption used primarily as fuel for ships including Samus' own. It is volatile and will ignite easily, and can be frozen by low temperatures. According to a creature log, it can give off toxic vapor. The Federation has control over distribution of the substance and proceeds from Bryyonian gel sales go directly to the Federation military forces protecting that sector of space. Space Pirates are said to desire the liquid so the Federation works to increase anti-piracy defenses. In some qualities, it's similar to Phazon, although not as powerful in energy output. It can be frozen and can damage the shielding in Samus' powersuit if she's in direct contact with the liquid gel. However once she gets the Hazard Suit it can't harm her. It is extremely rare, except on Bryyo, where there are lakes and rivers of fuel gel in the Bryyo Fire, which is the main source of the substance.

Interestingly, several different species have evolved not only to live in, but thrive on fuel gel, including Gel Rays, Gel Puffers, and Gelbugs.

It is likely that this source of fuel replaced Afloraltite.

Logbook entry
Metroid Prime 3: Corruption: "Fuel Gel is used to power most modern starships in the cosmos. It is extremely rare, and worlds that produce it tend to be quite prosperous. The exception to this is planet Bryyo, a Federation protectorate--and the largest supplier of Fuel Gel. Proceeds from Bryyonian gel sales go directly to the Federation military forces protecting that sector of space.

The sheer value of Fuel Gel is very attractive, and has led to an uprise in piracy over the last 20 years. Today, raids on gel transport convoys are common, especially in frontier regions of space. The Galactic Federation has increased antipiracy operations, and planets with Fuel Gel resources are protected by Federation fleets and ground forces."