Modifiers matching opal:

• expensive,
• common,
• synthetic,

Simple categories matching expensive:

• material,
• control,
• item,
• issue,
• fish,
• speaker,
• wood,
• equipment,
• boutique,
• metal,
• cereal,
• herb,
• ornament,
• steak,
• disease,
• mammal,
• bike,
• sweetener,
• coolant,
• part,
• component,
• furnishing,
• food,
• fiber,
• procedure,
• fabric,
• course,
• transport,
• flavouring,
• building,
• process,
• staff,
• test,
• nightspot,
• thing,
• silicon,
• shape,
• medicament,
• alloy,
• method,
• experiment,
• projector,
• softwood,
• debt,
• pastime,
• substrate,
• sport,
• antiquity,
• lock,
• rug,
• protection,
• toy,
• vinegar,
• modality,
• feature,
• pearl,
• trip,
• kimono,
• location,
• problem,
• element,
• assay,
• layer,
• agent,
• fibre,
• wine,
• peripheral,
• sulfide,
• flooring,
• outing,
• module,
• ink,
• cloth,
• intervention,
• medicine,
• clothing,
• essence,
• housing,
• polysaccharide,
• practice,
• assets,
• jewelry,
• ware,
• pharmaceutical,
• container,
• car,
• mechanism,
• catalyst,
• gem,
• decoration,
• arts,
• glass,
• opal,
• coenzyme,
• operations,
• facility,
• clutch,
• task,
• works,
• stone,
• school,
• boat,
• packaging,
• article,
• jewel,
• fruit,
• glassware,
• defense,
• endeavor,
• behaviour,
• mineral,
• condition,
• shopping,
• possession,
• service,
• upkeep,
• elements,
• loan,
• roller,
• apparatus,
• instrument,
• care,
• device,
• resin,
• textile,
• sounder,
• frill,
• examination,
• illness,
• fuel,
• appliance,
• discipline,
• seafood,
• research,
• spice,
• foodstuff,
• paraphernalia,
• workstation,
• oil,
• stuff,
• system,
• camera,
• property,
• unit,
• content,
• installation,
• drink,
• country,
• os,
• alcohol,
• object,
• mission,
• antidepressant,
• sensor,
• shellfish,
• conductor,
• change,
• platform,
• clothes,
• abrasive,
• antibiotic,
• extra,
• product,
• accessory,
• delicacy,
• software,
• treatment,
• weapon,
• cofactor,
• generator,
• essential,
• improvement,
• form,
• function,
• vessel,
• set,
• grain,
• furniture,
• structure,
• serum,
• compound,
• aggregate,
• measure,
• publication,
• coating,
• medium,
• footwear,
• assistance,
• machinery,
• devices,
• merchandise,
• restaurant,
• ceremony,
• fixture,
• filler,
• carpet,
• technology,
• security,
• solution,
• medication,
• gadget,
• study,
• hospital,
• club,
• activity,
• horse,
• tissue,
• benefit,
• arrangement,
• gas,
• program,
• substance,
• testing,
• tool,
• garment,
• investigation,
• management,
• tubing,
• event,
• fluid,
• vegetable,
• analysis,
• livestock,
• chemical,
• meat,
• plant,
• resource,
• penalty,
• hotel,
• souvenir,
• liquid,
• hardware,
• input,
• mailing,
• sector,
• mouse,
• flower,
• polymer,
• machine,
• endeavour,
• narcotic,
• fruitwood,
• condiment,
• fertilizer,
• repair,
• species,
• commodity,
• land,
• therapy,
• rubber,
• expert,
• animal,
• protein,
• horn,
• accoutrement,
• surface,
• chicken,
• creature,
• work,
• option,
• room,
• wax,
• paving,
• brush,
• bridge,
• institution,
• hardwood,
• instrumentation,
• feed,
• meal,
• perishable,
• beverage,
• gasket,
• shop,
• package,
• variety,
• vehicle,
• undertaking,
• drug,
• programming,
• ingredient,
• gear,
• area,
• organs,
• gemstone,
• artefact,
• computer,
• constituent,
• means,
• shed,