1 Definition
1.1 definisi
coal iku combustible-ireng coklat ireng utawa sedimentary rock biasane kedadean ing parang tingkat ing lapisan sing disebut kasur coal
obsidian punika kaca vulkanik alami kawangun minangka rock igneous extrusive. diprodhuksi nalika lahar felsic extruded saka gunung mbledhos ndingin kanthi cepet karo wutah kristal minimal
1.2 Sajarah
1.2.1 asal
1.2.2 panemu
1.3 Etimologi
saka col term english lawas, kang wis temenan Mineral karbon fosil wiwit abad kaping 13
saka obsidianus latin, misprint saka obsianus (lapis) (watu) saka obsius
1.4 kelas
rocks sedimentary
batuan beku
1.4.1 sub-kelas
awet rock, rock alus
awet rock, medium atose rock
1.5 kulawarga
1.5.1 group
1.6 kategori liyane
rock grained coarse, rock grained nggoleki, medium rock grained, rock opaque
rock opaque