Modifiers matching impurity:

• active,
• common,
• natural,
• physical,
• airborne,
• unwanted,
• harmless,
• volatile,
• dilute,
• lightweight,
• coarse,
• microscopic,
• absorptive,
• minor,
• little,
• gaseous,
• undesired,
• insoluble,
• fluid,
• environmental,
• atmospheric,
• minute,
• organic,
• foreign,
• inorganic,
• chemical,
• smaller,
• anionic,
• micro,
• residual,
• polar,
• particulate,
• small,
• dissolved,
• suspended,
• lighter,
• reactive,
• desirable,
• harmful,
• visible,
• mechanical,
• colloidal,
• random,
• out,
• soluble,
• damaging,
• heterogeneous,
• fine,
• interfering,
• light,
• sticky,
• hazardous,
• ordinary,
• biological,
• heavier,
• corrosive,
• ionic,
• stubborn,
• mental,
• off,
• separate,
• initial,
• possible,
• unavoidable,
• up,
• solid,
• homogeneous,
• mobile,
• nonpolar,

Simple categories matching heavier:

• body,
• textile,
• fabric,
• material,
• paint,
• metal,
• order,
• rock,
• item,
• machinery,
• plant,
• distillate,
• hardwood,
• contaminant,
• atom,
• pellet,
• soil,
• vehicle,
• thread,
• fuel,
• equipment,
• thing,
• gear,
• furniture,
• meal,
• element,
• mixture,
• papers,
• linen,
• sport,
• particle,
• electron,
• wood,
• industry,
• alcohol,
• vegetable,
• part,
• utensil,
• fixture,
• mineral,
• dish,
• deposit,
• glove,
• aircraft,
• activity,
• needle,
• fibre,
• foundation,
• camera,
• chemical,
• object,
• stain,
• clothes,
• impurity,
• unit,
• work,
• armament,
• substrate,
• stock,
• aggregate,
• fastener,
• job,
• halogen,
• constituent,
• paper,
• music,
• filament,
• ion,
• fare,
• pasta,
• construction,
• weaponry,
• surface,
• product,
• isotope,
• car,
• load,
• hadron,
• residue,
• clothing,
• gas,
• source,
• elements,
• transport,
• weapon,
• component,
• ship,
• sediment,
• ball,
• volatile,
• contamination,
• arms,
• medium,
• container,
• piece,
• fraction,
• sawdust,
• cake,
• commodity,
• stuff,
• fluid,
• agent,
• artifact,
• garment,
• style,
• tm,
• congener,
• substance,
• compound,
• package,
• article,
• meat,
• knit,
• line,
• grain,
• area,
• tool,
• implement,
• fish,
• leaf,
• solid,
• machine,
• liquid,
• alkane,
• dirtiness,
• meson,
• food,
• system,
• structure,
• instrument,
• bread,
• waste,
• scent,
• hydrocarbon,
• footwear,
• bird,
• conductor,
• post,
• alloy,
• lepton,
• decoration,
• sweetener,