40d:Stone

(For the beginning player, see also The Non-Dwarf's Guide to Rock)

---

Stone or rock is a naturally occuring solid aggregate of minerals. It sometimes leaves behind material after being mined or collapsing. Other types of minable tiles include soil and sand.

Stone is divided into a few key categories:

• Metal ore: stone that produces metal bars when smelted
• Rough gems: rough gems can be cut, then used to encrust objects and create windows.
• Other stone: Stone that is not an ore or a gem. Few of these have a use outside of items and structures. (Obsidian is one exception).

Economic stones are types of stone that can be reserved for a special purpose. For ores, this is smelting and for fluxes, this is steel production. Bituminous coal and lignite can be reserved for making coke.

Having created loose stone, many times you'll want to get rid of it or at least move it someplace else. See stone management for advice.

This article is about DF geology and the distribution of stones, and does not contain the specific locations of metal ores or gems.

Main layer types

There are four types of stone layers (plus soil, which is not stone). The type of layer is the primary indicator of what kind of ores you are likely to find on the map, as well as a sign of volcanic activity.

The types are sedimentary layers, igneous intrusive layers, igneous extrusive layers, and metamorphic layers.

The primary types of rock only occur in their own layers. (e.g. you won't find limestone in a marble layer.)

Stones forming entire layers

These types of stone occur as entire layers, containing some veins and pockets of other minerals (see below). If one of the following types of stone is present on your map, it will be listed in one of the biomes on the embark screen.

Sedimentary	Igneous intrusive	Igneous extrusive	Metamorphic
░ ● Chalk = ● Chert , ● Claystone ∞ ● Conglomerate ` ● Dolomite ▓ ● Flint ▓ ● Limestone ≈ ● Mudstone # ● Rock salt # ● Sandstone . ● Shale % ● Siltstone	░ ● Diorite ▒ ● Gabbro ▓ ● Granite	∞ ● Andesite # ● Basalt . ● Felsite ▒ ● Obsidian , ● Rhyolite	= ● Gneiss ▓ ● Marble - ● Phyllite - ● Quartzite ` ● Schist % ● Slate

Other Stone

Stones found on this table will occur as pockets and veins inside their respective stone layers (see above). When your miners newly encounter one of them, the game will pause and you will receive an announcement; even for the ones that have no use other than to build constructions of unusual colors. Note that the veins or clusters can spread into other layers, and may cause some layers to contain stones they usually wouldn't. A few of these stones, such as Olivine, have other, more interesting minerals appear inside them.

Non-layer stone formations occur in one of three shapes: large clusters, veins, and small clusters. (See Veins & Clusters for full info.)

The following table does not contain ores and gems. The types of stone listed here that do not link to their own article are generic.^{v0.28.181.40d}

Icons	Name	Found in	Found how	Special source of
^ ●	Alabaster	Gypsum	Small clusters	Ordinary stuff
` ●	Alunite	All Igneous extrusive, Kaolinite	Large clusters	Ordinary stuff
v ●	Anhydrite	Gypsum, Satinspar, Alabaster, Selenite	Single	Ordinary stuff
+ ●	Bauxite	All Sedimentary	Large clusters	(star) rubies, (star) sapphires, Variscite
☼ ☼	Bituminous coal	All Sedimentary	Veins	Fuel
` ●	Borax	Gypsum, Rock salt	Small clusters	Ordinary stuff
% ●	Brimstone	All Igneous extrusive, Gypsum	Small clusters	Ordinary stuff
" ●	Calcite	Limestone, Marble	Small clusters	Ordinary stuff
= ●	Chromite	Olivine	Veins	Native platinum,demantoid
£ *	Cinnabar	All Igneous extrusive, Shale, Quartzite	Veins	Ordinary stuff
£ *	Cobaltite	All Igneous All Metamorphic	Veins	Ordinary stuff
- ●	Cryolite	Granite	Small clusters	Ordinary stuff
o ●	Graphite	Gneiss, Quartzite, Marble, Schist	Small clusters	Ordinary stuff
# ●	Gypsum	All Sedimentary	Large clusters	Ordinary stuff
" ●	Hornblende	All Igneous, All Metamorphic	Small clusters	Ordinary stuff
. ●	Ilmenite	Gabbro	Small clusters	Ordinary stuff
░ ●	Jet	All Sedimentary	Large clusters	Ordinary stuff
= ●	Kaolinite	All Sedimentary	Large clusters	turquoise
% ●	Kimberlite	Gabbro	Veins	diamonds,Black pyrope,Red Pyrope,Rhodolite
* ●	Lignite	All Sedimentary	Veins	Fuel
% ●	Marcasite	Kaolinite	Small clusters	Ordinary stuff
v ●	Mica	All Metamorphic, Granite	Large clusters	Ordinary stuff
% ●	Microcline	All Stone	Large clusters	Ordinary stuff
% ●	Olivine	Gabbro	Large clusters	Native platinum
- ●	Orpiment	All Igneous extrusive	Small clusters	Ordinary stuff
% ●	Orthoclase	All Igneous intrusive, All Metamorphic	Large clusters	Ordinary stuff
, ●	Periclase	Marble	Small clusters	Ordinary stuff
% ●	Petrified wood	All Sedimentary	Small clusters	Ordinary stuff
* ●	Pitchblende	Granite	Small clusters	Ordinary stuff
Θ ●	Puddingstone	Conglomerate	Large clusters	Ordinary stuff
% ●	Pyrolusite	All Igneous	Small clusters	Ordinary stuff
% ●	Realgar	All Igneous extrusive	Small clusters	Ordinary stuff
` ●	Rutile	All Metamorphic, Granite	Small clusters	Ordinary stuff
x ●	Saltpeter	All Sedimentary	Small clusters	Ordinary stuff
- ●	Satinspar	Gypsum	Small clusters	Ordinary stuff
; ●	Selenite	Gypsum	Small clusters	Ordinary stuff
≈ ●	Serpentine	Olivine	Small clusters	Ordinary stuff
% ●	Stibnite	All Igneous extrusive	Small clusters	Ordinary stuff
= ●	Sylvite	Rock salt	Large clusters	Ordinary stuff
| ●	Talc	Dolomite	Large clusters	Ordinary stuff

DF Geology and real-world Geology

The geology and stones of Dwarf Fortress are based on real-world geology and mineralogy. To understand the terms used here, you may want to crack open a geology textbook (a high school one should suffice). If you don't happen to have one close by, the Wikipedia articles for geology, mineralogy, or the terms in question might help.