Possible Clues:

• Succeeded with difficult piece of pottery
• Dig discovery
• School can be difficult for one who's smashed
• Broken piece of a brittle artefact
• Sharp glass fragment
• Call for silence before artist returns diamonds with piece of broken glass
• Piece of something brittle
• Piece of pottery, for example, obtained from small firm
• Go well with; attire
• Fragment soft and hard