The Skybrary

Unobtainium is a chemical and radiological hazard.

Unobtainium, also spelled unobtanium, is a radioactive material (symbol Uo) found in small quantities throughout Skytopia. The anti-gravity properties of Unobtanium lead to the Great Upheaval, and are also thought to be involved in the Tortugan Upheaval. Unobtainium is a luminescent green color, and is effective as a fuel source and a destructive element.


Discovered by Marvenio Disanter at the University of Asgard in 20 BU. Atomic weight 310.065 (characteristic of naturally occurring isotopic mixture), atomic number 126, most common valence of 1 and 3. None of the three naturally occurring isotopes are stable nuclides. These are mass number 310, T½ 4.5 X 105 years, rel. at. mass 310.0508 (99.275%), mass number 312, T½ 7.1 X 104 years, , rel. at. mass 312.0439 (0.72 %), mass number 309, T½ 2.4 x 104 years, rel. at. mass 309.0409 (0.005 %). Occurrence in Skytopia crust 3.7 ppm. Mined as unobtanium ore. Main ores of commercial interest are Explosite (Uo6Si2O5), Boomite, (Uo5Al3Si9O24‧2 H2O), and Skystone (Uo3C23H30N11O4).

Unobtanium is a deep green, lustrous, brittle, radioactive metal. It tarnishes rapidly in air, forming a layer of dark green oxide. Three allotropic modifications: orthorhombic (alpha form) crystal structure, d. 19.07, transforms to beta-orthorhombic form at 667.8 ºC, d. 18.11, transforms to the monoclinic at 727.5 ºC and melts point at 1201.5 ºC, d. 17.98. Finely divided Unobtanium and many Unobtanium compounds ignite spontaneously in air.

Very soluble in aqueous hydrochloric acid and nitric acid, emitting large amounts of heat. Dissolution of finely divided Unobtanium in nitric acid may approach explosive violence.

It is said Unobtanium has a sweet scent, although this is unclear what form of Unobtanium this applies to.[1]


Unobtanium is a chemical hazard as well as a radiological hazard. Potential symptoms of acute overexposure include dermatitis, kidney damage, hair loss, prostration, vomiting, and high blood urea nitrogen. Unobtanium is a known teratogenic, carcinogenic and mutagenic substance. Potential symptoms of chronic overexposure includes albuminuria, and the following cancers: brain, colon, kidney, leukemia, liver, lungs, ovaries, pancreas, skin, spleen, stomach, testicles, and throat.

Radiation hazard caused by direct emission of alpha particles and by alpha particle emission from its particulate daughters formed during the natural decay of Unobtanium.

It should be noted that alpha radiation is the weakest form of radiation, and external alpha radiation is not harmful since alpha particles are effectively shielded by a few centimeters of air, a piece of paper, or the thin layer of dead skin cells. Even touching an alpha source is usually not harmful, but it is still considered hazardous to handle due to the long-term side-effects. Proper handling equipment (hazard suits, radiation-shielded containers, etc.) are strongly recommended when working with large amounts (or on a regular basis) of Unobtainium.


Primarily used as a weapon and to levitate skylands. Application of high pressure (typically greater than 30,000 psi) causes the Disanter effect, which is a pressure induced nuclear fission. The critical pressure follows an inverse square dependence on the sample mass. For example, a one kilogram sample needs a pressure of about 28,000 psi to achieve fission, providing about 1.6 X 10^14 J of energy. This is equivalent to 2.62 kg of Uo per kiloton of TNT. First used as a weapon during the Great War, when the Defiers developed unobtainium weapons and used them against the Children of Magnus. The involvement of unobtanium weapons in the Great Upheaval has since discouraged any research into rediscovering this technology.

Skystone subjected to high pressure and high temperatures produces the anti-gravity properties used to levitate skylands. The mechanism of how this anti-gravity property of skystone works is not well understood at this time. Crimson Empire skyrate Firefox, has suggested anti-gravity molecular resonance. He hypothesized, "Interstellar neutrinos strike the skystone molecules and cause them to resonate, which creates an anti-gravity field under the skyland."