Related Clues:

• Sedimentary deposit
• Slimy mud
• Modeler's need
• Pot composition
• Wind-borne silt deposit
• Windblown topsoil component
• Bank deposit of a sort
• Molding material
• Riverbed crud
• See 17 Across
• Deposit at the mouth of a river
• Gardener's soil, perhaps
• Tandoor material
• Potter's buy
• Alluvial deposit