Related by context. Frequent words. (Click for all words.) 68 iron oxides 64 olivine 63 calcite 62 magmas 62 hydrothermal breccia 62 basaltic 61 hydrothermal activity 61 clasts 60 silicates 60 spinel 60 perovskite 60 solar nebula 60 silicate 60 lavas 59 monazite 59 chalcocite 59 siliceous 59 manganese oxide 59 sulphates 59 pyroxenite 59 igneous rocks 59 protoplanetary disk 59 vacuoles 59 gossans 59 igneous rock 59 copper oxides 59 vuggy silica 59 quartz veinlets 58 marine sediments 58 metamorphic rocks 58 spherules 58 biotite 58 aragonite 58 apatite 58 carbonaceous 58 isotope ratios 58 calcareous 58 sulphide minerals 58 zircons 58 electron density 57 osmium 57 pyroclastic 57 oxygen isotopes 57 surficial 57 hornfels 57 hydrothermal breccias 57 pyrite chalcopyrite 57 meteorite impacts 57 hydrothermally altered 57 potassic alteration 57 planetesimals 57 igneous 57 schists 57 gabbro 57 basalts 57 ejecta 57 Archaean 57 jasperoid 56 oxidised 56 feldspar 56 bornite 56 limonite 56 supergene 56 potassic 56 noctilucent clouds 56 peridotite 56 chlorite 56 ultramafic rocks 56 isotopic 56 silicon atoms 56 graphitic 56 kimberlite indicator minerals 56 isotopic composition 56 Sediments 56 mudstone 56 silica 56 icy crust 55 crystalline structure 55 galena 55 waxy substance 55 hematite 55 iron oxide 55 sedimentary rock 55 sulfides 55 hydroxyapatite 55 hydrothermal alteration 55 stromatolites 55 argillic alteration 55 magmatic 55 breccia pipes 55 lunar soil 55 pyrite mineralization 55 calcrete 55 chromophore 55 skarns 55 micelles 55 tuffs 55 polar vortex 55 lake sediments 54 aerosol particles 54 lava tubes