Lining the magma flow
Obsidian is a dark stone with greater value than any other type of stone: obsidian items are worth three times as much as those made from normal rock. Obsidian can be found in abundance in a narrow strip on either side of the magma flow and in smaller clusters strewn throughout the mountain.
If the magma flow floods when it is first discovered, any magma that is released will cool into obsidian which can then be mined out again. However, deliberate flooding of magma (using floodgates) will not leave behind any obsidian.
At a craftsdwarf's workshop, "dark stone short swords" can be made out of obsidian (this also requires one piece of wood for the hilt). These obsidian swords are as effective as steel, doing 133% damage (relative to iron). Toady had stated that he intended for these swords to wear away much faster than those made of metal, though this had not yet been implemented.
"Obsidian" is the also name of the twelfth month of the dwarven calendar, covering late Winter.
|Gray||Andesite • Basalt • Chalk • Diorite • Dolomite • Felsite • Flint • Gneiss • Granite • Pumice • Rhyolite • Sandstone • Schist • Shale • Siltstone • Slate • Talc|
|Light||Limestone • Marble • Moonstone|
|Dark||Jet • Obsidian • Onyx|
|Ore||Adamantine, raw • Cassiterite • Coal • Galena • Gold, native • Hematite • Malachite • Platinum, native • Sphalerite|