Related Clues:

• Perhaps a barrier is made of little stones like these
• Stones that set up 27 across
• Little stones, as they are around the way in
• Stones might get the gas around 23 down
• A barrier that's composed of little stones
• Seems a way in makes them rather precious
• The senior Muslim gets set up in a semi-precious way for them
• A barrier is a just a bit precious for them
• Ancient May birthstones
• Swirly marbles
• Banded marbles
• A new stage setting may include them
• Name for stones when placed round an entrance
• On reflection, they're a great help for motorists
• Forms of silica used by a computer expert