40d:Economic stone

Economic stones have special uses as ore, fuel or flux, or other uses like making special items. You can use the z : Stone menu to restrict or un-restrict their use in items and buildings. In technical terms, an economic stone is any stone which can be used as a reagent in any form of reaction. Obsidian and Bauxite are exceptions, as they can be used to make swords and magma-safe mechanisms respectively.

The Stone menu will also show what each stone can be used for--very useful for figuring out what you need to mine to make that obscure metal your noble is whining about.

Stone name	Found in	Found how	Use	Value	Icons
Obsidian	Igneous extrusive	Full Layers	Swords	3	▓
Calcite	Limestone, Marble	Small clusters	Flux	2	"
Chalk	Sedimentary Layer	Full Layers	Flux	2	░
Dolomite	Sedimentary Layer	Full Layers	Flux	2	`
Limestone	Sedimentary Layer	Full Layers	Flux	2	▓
Marble	Metamorphic Layer	Full Layers	Flux	2	▓
Bituminous coal	All Sedimentary	Veins	3 Coke	1	☼
Lignite	All Sedimentary	Veins	2 Coke	1	*
Bauxite*	Sedimentary Layer	Large clusters	Magma-safe mechanisms	1	+

• Though technically not an economic stone, Bauxite is included here for the players' sake considering its special case