I may have messed with these since then, but these should have been reverted to the raws I used for the gas chamber. Let me know if they don't work.
[MATGLOSS_STONE:HIDDEN_FUN_STONE]
[NAME:HIDDEN FUN STONE][COLOR:5:7:1][TILE:'H']
[ITEM_SYMBOL:'*']
[VALUE:1500]
[MELTING_POINT:0]
[BOILING_POINT:1]
[SOLID_DENSITY:1]
[ENVIRONMENT:IGNEOUS_EXTRUSIVE:VEIN:100]
[ENVIRONMENT:IGNEOUS_INTRUSIVE:VEIN:100]
"HIDDEN FUN STONE," was something I made to make mining more of a pain in the ass in a mod I lost interest in. Although I made a few minor releases of the mod, I don't think I ever told anyone about the HIDDEN FUN STONE, which may have caused a few bursts of angry rage now and then, a few seconds after someone discovered it for the first time.
[REACTION:DETONATE_URANIUM]
[NAME:detonate smelter]
[SMELTER]
[REAGENT:1:BAR:NO_SUBTYPE:METAL:xxxx]
[PRODUCT:100:50:STONE:NO_SUBTYPE:STONE:HIDDEN_FUN_STONE]
Add [FUEL] to the end of the second one, if you so wish. The enriched uranium I made was hard to come by, so substitute any metal you wish (or stone, though that requires the item tag for stone), though I can give you the raws I used for the uranium if you want them. You can also change the names of the reaction, maybe to DETONATE_GRANITE and "gas chamber," or something. I don't care.
Again, let me know if they don't work. A few important-looking lines from the error log would also be helpful.
Don't forget, it won't blow holes in walls like the topic creator wanted, it just kills creatures.