Rhyolite

Stone
Sedimentary	Sandstone • Siltstone • Mudstone • Shale • Claystone • Rock salt • Limestone • Conglomerate • Dolomite • Flint • Chert • Chalk
Igneous I.	Granite • Diorite • Gabbro
Igneous E.	Rhyolite • Basalt • Andesite • Felsite • Obsidian
Metamorphic	Quartzite • Slate • Phyllite • Schist • Gneiss • Marble
Unique	Bauxite • Lignite • Bituminous coal • Graphite • Kimberlite
Ore	Bismuthinite • Cassiterite • Copper nuggets • Galena • Garnierite • Gold nuggets • Hematite • Horn silver • Limonite • Magnetite • Malachite • Native aluminum • Platinum nuggets • Raw adamantine • Silver nuggets • Sphalerite • Tetrahedrite

Rhyolite
Uses
	Masonry ; Stone crafting ; Construction ;
Properties
	Igneous extrusive layer ; Material value 1 ;
Contains
	Hematite (Veins) ; Native gold (Veins) ; Native copper (Veins) ; Tetrahedrite (Veins) ; Native aluminum (Small Clusters) ; Galena (Veins) ; Brimstone (Small Clusters) ; Realgar (Small Clusters) ; Orpiment (Small Clusters) ; Stibnite (Small Clusters) ; Rutile (Small Clusters) ; Hornblende (Small Clusters) ; Alunite (Large Clusters) ; Microcline (Large Clusters) ;
	Wikipedia article

Rhyolite is one of the types of stone that forms entire layers.

It is currently^{v0.28.181.40d} identical in all ways to 3 of the other 4 igneous extrusive stones: andesite, basalt, and felsite (obsidian being the sole exception).