Modifiers matching rock:

• sedimentary,
• unusual,
• hard,
• barren,
• heavier,
• volcanic,
• igneous,
• soluble,
• weak,
• metamorphic,
• flinty,
• large,
• looking,
• difficult,
• intermediate,
• heterogeneous,
• spherical,
• crystalline,
• solid,
• acid,
• plutonic,
• powdered,
• crustal,
• granular,
• porous,
• permeable,
• soft,
• elastic,
• homogeneous,
• isolated,
• textured,
• reflective,
• primary,
• argillaceous,
• terrestrial,
• refractive,
• widespread,
• heated,
• related,
• fine,
• free,
• indigenous,
• coloured,
• russian,
• suitable,
• ductile,
• impermeable,
• crushed,
• surrounding,
• carbonaceous,
• anisotropic,
• simple,
• geological,
• underlying,
• coarse,
• abrasive,
• fragmented,
• magnetic,
• tight,
• original,
• molten,
• brittle,
• polished,
• extrusive,
• acidic,
• red,
• alkaline,
• softer,
• artificial,
• angular,
• nonporous,
• subsurface,
• durable,
• ordinary,
• dry,
• marine,
• colored,
• competent,
• intrusive,
• unstable,
• glassy,
• siliceous,
• impenetrable,
• british,
• smooth,
• colorful,
• small,
• common,
• weaker,
• hardest,
• inappropriate,
• white,
• fragile,
• insoluble,
• local,
• modern,
• stronger,
• clastic,
• covered,
• conductive,
• refractory,
• noble,
• lightweight,
• older,
• egyptian,
• sedentary,
• massive,
• sharp,
• organic,
• size,
• azonic,
• chemical,
• eruptive,
• dated,
• firm,
• light,
• hot,
• impervious,
• ornamental,
• ingenious,
• calcareous,
• reactive,
• rough,
• tough,
• industrial,
• combustible,
• typical,
• resistant,
• opaque,
• stable,
• rich,
• enough,
• natural,
• strong,
• uniform,
• basic,
• flat,
• sticky,
• deleterious,
• polyphase,
• lighter,
• smaller,
• traditional,
• friable,
• extraterrestrial,
• unconsolidated,
• dense,
• inert,
• vitreous,
• aluminous,
• exotic,
• abundant,
• heavy,
• frozen,
• consolidated,
• pulverized,
• normal,
• polycrystalline,
• bituminous,
• native,
• rigid,
• available,
• metallic,
• dark,
• compact,
• flying,
• new,
• useful,
• geologic,
• crumbly,
• visible,
• good,
• virgin,
• planetary,
• decorative,
• base,
• non-porous,
• precious,
• korean,
• salt,
• harder,
• loose,

Simple categories matching opaque:

• rock,
• object,
• component,
• material,
• item,
• aggregate,
• system,
• gemstone,
• beverage,
• conductor,
• stone,
• document,
• structure,
• surface,
• contaminant,
• article,
• metal,
• adhesive,
• imperfection,
• substrate,
• fluid,
• coating,
• sack,
• solid,
• liquid,
• gem,
• film,
• part,
• image,
• product,
• bag,
• substance,
• container,
• particle,
• paper,
• pigment,
• creature,
• assembly,
• matter,
• plastic,
• tissue,
• content,
• paint,
• mark,
• sheet,
• glass,
• filler,
• foodstuff,
• layer,
• matrix,
• symbol,
• body,
• powder,
• oxide,
• cell,
• obstacle,
• original,
• obstruction,
• picture,
• barrier,
• sunscreen,
• copy,
• fiber,
• web,
• fence,
• fabric,
• ingredient,
• mineral,
• language,
• ink,
• medium,