Possible Clues:

• Fragments of transparent quartz
• Turn on the waterworks for last shift producing endless pieces of cut glass
• Pieces of colourless transparent quartz
• Watch-face covers
• Ice needles, e.g
• What makes sugar? Class try to form them
• Group produced by Phil Spector, with 'the'
• Clear quartz pieces
• Cave formations
• Rocks formed by the solidification of a substance