I theorized a while ago that the sparks (tokens) dropped from treasure chests could be linked either to the level's monster theme OR to its status theme, but had to be linked to at least one of them (note: this is the LEVEL's theme, not necessarily the STRATUM's theme). These associations would be the same as Brinks' trinkets, i.e.

• Primal Sparks come from piercing monsters (beast, slime) and the freeze status
• Forge Sparks come from elemental monsters (construct, probably gremlin) and the fire and shock statuses
• Grim Sparks come from shadow monsters (fiend, undead) and the poison status
• Treasure Vaults drop all type of sparks.

I've been recording all the sparks I've found to try to support or disprove the theory. Here's what I've got:

Beast/Poison Theme: 1 grim spark

Slime/Freeze Theme: 3 primal sparks
Slime/Fire Theme: 8 primal sparks, 1 forge spark
Slime/Poison Theme: 2 primal sparks (from a single danger room)
Slime/- Theme (RJP): 33 primal sparks

Construct/Freeze Theme: 9 primal sparks, 5 forge sparks
Construct/Fire Theme: 3 forge sparks
Construct/Poison Theme: 3 forge sparks, 2 grim sparks
Construct/- Theme: 1 forge spark

Fiend/Freeze Theme: 1 primal spark
Fiend/Shock Theme: 1 grim spark

Undead/Freeze Theme: 1 grim spark
Undead/Fire Theme: 1 forge spark, 2 grim sparks
Undead/Shock Theme: 6 forge sparks
Undead/Poison Theme: 1 grim spark

That's a total of 84 sparks, and all the data so far is consistent with my hypothesis. Most levels only have 1 type of spark that could disprove my theory, but if sparks were actually uniformly distributed, there's less than 1 chance in 10^27 that all of the above sparks would just happen to be consistent with the themes.

Anyone want to propose another explanation, or shall I assume this is correct and edit the wiki accordingly?