Every system not in stasis has fire, at least on some level. For most systems this fire is more or less metaphorical, never seen and the effects never felt, at least not directly1. But other systems manifest their fire in blatant, noticeable ways.
Most often this happens during ‘novas’, when the amount of change in a system undergoes a massive spike suddenly. If the evolution of flowering plants on Earth were speeded up to happen in hours, then one might see a novaing of greenfire. Such a nova would be short-lived, of course, since fire novas require a constantly changing system to be sustained. But during the process, the source of the fire (plants, in this case) would be reinforced by the fire. In this example, plants would grow rapidly—under the influence of greenfire, mature forests can grow in a few days.
When a fire nova does happen, it spreads along the source of the fire. When there is a greenfire nova, the greenfire leaps from plant to plant, spreading along all surfaces of living plant matter. The area affected by the fire is limited by how drastic the spike in the amount of change is; a Seeder device2, after having landed on a lifeless planet, can produce enough greenfire to cover the whole planet—one reason why they are used.
[…] the color of the fire is dependent on the source. Moonfire is softly luminescent silver, sunfire is golden with flecks of iridescent orange and red, greenfire is bright green, oceanfire is deep blue,[…]
In all my readings, I have only come across one way to contain fire: glass. The metaphysical properties of glass, once it is properly prepared, enable it to redirect metaphysical energy, so that metaphysical energy that would otherwise dissipate is forced back inwards. These properties are the reason glass is used by the planet bonsai masters of Barmal—the same individuals who first perfected the technique of containing fire.
The same technique can be used to imprison an elemental3. Because the glass may also be subjected to physical force, it must be reinforced, which can be difficult to do without ruining the metaphysical properties of the glass; alternatively it may simply be embedded in concrete or metal. Many instead opt to use magical wards, though I would recommend against this, given that they tend to weaken over time due to exposure to the elements if not specifically spelled against it, and also are a trifle obvious.
[The rest of the page was wiped clear and had written on it in natural plant dyes ‘Contained instructions on how to bud off a section of reality to trap an elemental, or any other being. Determined possibility of it being used against an archetypal manifestation and tossing everything associated with them into a separate reality as too great. – Greenleaf’]