Inspired by some of Hexyle's lore threads concerning how our weapons worked.

I'm not quite sure if this belongs in general, but Treasure Vault and Arsenal didn't quite seem to fit.

Tearium: Used in the construction of Isoran energy cells, Tearium has the unique characteristic of generating alpha radiation when exposed to (as of current knowledge) any type of energy.. (Canon: First mentioned in the Spiral Knights intro, where Captain Ozlo remarks that "we won't just find several thousand tons of Tearium lying around on the surface of the planet to repair the Skylark's power core".)

Energy cells: Isoran energy cells are used to power almost all aspects of Spiral Order technology, from field scanners to personal weapons to starships. Each energy cell contains a small shard of Tearium, which is fed by several receptacles designed to harness latent energy in the area, among them thermal and solar energy. At each end of the Tearium shard is a miniaturized generator designed to convert alpha radiation into electricity.
The "D" class energy cell is by far the most common type used by the Spiral Order, and is used to power various types of field equipment. Each D-class energy cell is rated to withstand a temperature of 1500 Farenheit for 5 minutes and 15000 units of atmospheric pressure for 7 minutes, thanks to a layer of synthetic alloy on the cell's exterior. The same alloy is also used in several Spiral Order armor suits and shields, as well as the exterior of escape pods.
(Fun fact: Many Knights on expeditions in the Clockworks charge their energy cells by placing them in a campfire overnight.)

Molecular disruption technology: First discovered by Isoran researchers in 2145 PMW (Pre Morai Wars), molecular disruption technology is utilized on almost all standard-issue Spiral Order melee weapons such as the Calibur line of swords. The underlying principle behind the technology works by flooding an area with streams of neutrons, negating positive and negative charges in said area and causing ionic and covalent bonds to break down. However, the neutron streams are only effective at short distances in atmosphere due to the air absorbing most of the stream before it reaches the target, limiting the technology to personal melee weapons and anti-starship cannons designed for use in a vacuum.

Objects cut by molecular disruption are almost perfectly smooth to the unaided eye.

I'll think up of some more stuff later. Until then (and after then), feel free to add your own ideas of lore that the ingame flavor text didn't touch on.