Parabiological, mineral-based, high temperature, pre-sentient lifeforms

Two Rheolithoids
Image from Steve Bowers
Two Rheolithoids inside a body of molten rock, apparently interacting in some way; possibly communicating, fighting or mating. Image created by a geophysical deep scan system.
Rheolithoids are organisms that thrive inside molten magma layers, either deep within a rocky world or in liquid lava flows at the surface. They consist entirely of specialised mineral-like structures, some of which are solid in form and retain their complex shapes, while other structures in the organism are plastic or fluid, and these are capable of controlled movement.

The first Rheolithoids were discovered in 2546 AT on Cherufe, an Ionian subtype world orbiting JD 13188094 (a red dwarf ten light years from HD 2954/BD+15074 in Pisces). A Silicon Generation survey team found evidence of organised structures in certain essential pyroclasts which had been ejected from several equatorial volcanoes. These organised structures resembled living creatures in many ways, although all the examples found were inactive and presumed to be 'dead'.

The Generation geologists used a lithosphere probe to search beneath the crust of this small world, in an attempt to find more of these organised structures. The probe consisted of a lava-resistant drill bit, equipped with sensors, and reinforced with an invisibly-thin tube of magmatter which would cool the probe while acting as a data channel back to the surface. Using the probe they discovered a connected series of volcanic pipes and sills girdling the globe, with a continuous fluid lava environment permitting free movement of material. Within these magma chambers, 5-40 km under the surface, native rocks are broken and comminuted, melted and changed in a high energy environment. In this hot, semi-fluid environment the organised structures were observed to be active and behaving in a life-like manner. The Generation geologists named them Rheolithoids, because of their flowing, plastic nature.

Individual Rheolithoids are composed from complicated interwoven silicaceous minerals such as kalsilite and melilite, together with numerous impurities such as germanium, selenium and rare-earths. These entities take the form of discrete, self-replicating, life-like systems capable of growth, and are generally more than a metre in length.

The Silicon Generation crystallographers studied these entities for hundreds of years, using a range of geophysical sensors, and also dissection of non-active specimens. Eventually they produced a detailed description of the creatures.

Ever since their discovery there has been debate about whether these entities can be truly considered to be alive, but they display most, if not all, of the characteristics of a living entity. Many taxonomists classify these entities as life-like organisms or parabiological systems rather than true biology.

In 2763 AT another world was discovered which supported Rheolithoid-type organisms. This world was given the name Natfaire. The creatures on this world were different in detail to those found on Cherufe, but had several similar characteristics. Since that time several hundred similar magmatic biospheres have been discovered. The prevalent theory concerning the origin of these worlds is that they were seeded many millions of years ago by a xenosophont civilisation, since these life-like organisms have too many characteristics in common to have arisen by chance.


The core of a Rheolithoid is a fine-grained nucleus of interwoven minerals, apparently related to a vortex crystal formation, but with a consistent asymmetrical organisation that is recognisably similar from one individual to another. Individuals are usually 0.1 to 10 metres in diameter, and mostly sessile, sometimes moving slowly towards a source of comminuted minerals or to avoid being absorbed by a larger individual. Wild Rheolithoids are no more self-aware than many sessile animals in an organic biota; they are comparable in intelligence to a sea anemone.

Information for the perpetuation of the organised system is stored in germanium and selenium intercalated in tiny data rich flat plaque minerals, while response to the environment is transmitted by slow oscillating reactions in glassy zeolites regulated by cation inclusions acting as messengers to and from the nucleus. The oscillating reactions cause tiny rotating cells to establish in the semimolten zeolite integument, permitting movement towards or away from stimuli. Rheolithoids sense their environment by absorbing fine material between these rotating cells, which is then tested by an array of subcutaneous reactant mineral micrograins. Energy is stored in the rotating cells and in endothermic crystallization reactions.

Magmatic lifeforms - later developments

The Generation found another Ionian subtype world orbiting the nearby star BD+15.4074B, and attempted to recreate a suitable magmatic environment for Rheolithoids, succeeding in 3665. Since that time a wide range of modified forms have been developed, capable of thriving in several different ignean environments.

Silicon Generation researchers managed to produce a provolved intelligent form by 5080. These high-temperature sophonts, known as Efrits, have become widely distributed in magmatic environments around the Terragen Sphere, on Hephaestian worlds, Pyrothalassic worlds, in subcrustal magma environments, and even in artificial high-temperature megastructures; they have also found a niche in other high energy environments such as fusion drive cooling systems on Generation ships.

Life-like Processes

A variety of similar life-like parabiological organisms have been discovered in various locations in the universe, existing in various environments, some of which are natural, and others have been created artificially (either by Terragen engineers or by xenosophonts). A life-like system should fulfil certain criteria; autonomous acquisition of nutrients leading to growth, the use of energy to grow and/or move and/or maintain a consistent internal state, reproduction and the capacity to retain the information required for reproduction, response to stimuli, and (probably) the capacity to evolve. The complexity of carbon-based organic molecules is known to permit all these qualities, but other systems also permit similar processes to occur, and the Rheolithoids are good examples of such life-like organisms.

Related Articles
Appears in Topics
Development Notes
Text by Steve Bowers - updated 2020
Initially published on 20 October 2002.