Related Clues:

• Ace maybe filling in bowled no maiden over
• The hard stuff suited one
• Form of carbon that might be useful in dating?
• Solitaire, e.g
• Matt finish in mind around one card
• Emerald or diamond
• April birthstone
• Ruby or pearl
• Polished stone
• Lapidary's specimen
• It may be cut or paste?
• Pearl Margaret picked up
• Stone used in jewellery
• Rock singer
• This card could be an ace