Simple categories matching igneous:

• material,
• stone,
• activity,
• rock,
• mineral,
• character,
• process,
• structure,
• body,
• event,
• formation,
• intrusion,

Members with property igneous:

• anorthite,
• minor_andesite,
• basalt,
• granite,
• quartz_diorite,
• basaltic_rock,
• acid_tuff,
• rhyolite,
• assimilation,
• andesite,
• crystallization,
• sedimentary_rock,
• quartz,
• peridotite,
• gabbro,
• dacite,
• olivine,
• chromite,
• intrusion,
• obsidian,
• amphibole,
• hotspot_track,
• volcanic_lava,
• talc,
• gneiss,
• quartz_vein,
• crystal_fractionation,
• sill,
• diorite,
• granitic_batholith,
• feldspar,
• pegmatite,
• olivine_gabbro,
• oxide,
• volcanic_ash,
• volcanic_obsidian,
• basaltic_lava,
• fractionation,
• lustrous_stone,
• clay,
• mica,
• pyroxene,
• basaltic_andesite,
• porphyry,
• hornblende_gneiss,
• mica_gneiss,
• steatite,
• baddeleyite,
• schist,
• pitchstone,
• stone,
• asbestos,
• partial_melting,
• augite_porphyry,
• granite_fig,
• zircon,
• vishnu_schist,
• fractional_crystallisation,
• chlorite,
• granite_gneiss,
• sills,
• volcanic_eruption,
• equilibrium,
• dike,
• sedimentation,
• apatite,
• crystal_accumulation,
• biotite_gneiss,
• ilmenite,
• contact_metamorphism,
• garnet,
• lava,
• basaltic_flow,
• igneous_differentiation,
• shale,
• intrusion_breccia,
• batholith,
• fractional_crystallization,
• biotite,
• magma_fragmentation,
• stock,
• plagioclase_feldspar,
• hornblende,
• mare_basalt,
• slate,
• rounded_zircon,
• kimberlite,
• bubble_growth,
• metamorphic_rock,
• tuff,
• plagioclase,
• monazite,
• lava_flow,
• volcanic_rhyolite,
• quartzite,
• augite,
• amphibolite,
• differentiation,
• basalt_form,
• rhyolite_sills,
• volcanism,
• magnetite,
• marble,
• albite,
• similar_rock,
• mantle_rock,
• vent,
• pumice,
• boulder,
• igneous_rock,
• orthoclase_feldspar,