Modifiers matching currency:

• foreign,
• electronic,
• international,
• external,
• standard,
• stable,
• physical,
• real,
• world,
• local,
• monetary,
• harder,
• major,
• single,
• larger,
• native,
• national,
• valuable,
• key,
• common,
• traditional,
• primitive,
• everyday,

Simple categories matching harder:

• particle,
• stone,
• substrate,
• deposit,
• material,
• currency,
• stimulant,
• surface,
• sport,
• metal,
• sediment,
• stuff,
• drug,
• thing,
• work,
• boot,
• pin,
• layer,
• genre,
• substance,
• filler,
• medium,
• gemstone,
• structure,
• crystal,
• feldspar,
• narcotic,
• wood,
• resin,
• music,
• powder,
• tissue,
• rock,
• cheese,
• object,
• glass,
• aggregate,
• abrasive,
• part,
• ingredient,
• fabric,
• mineral,
• ground,
• alloy,
• formation,
• polymer,
• food,
• agent,
• assets,