Possible Clues:

• Crystalline mineral
• Rock-forming mineral that makes up over half of the earth's crust
• Mineral left with diamonds in iron box
• One should evacuate WC, given standard deposits of igneous rock
• Fellow pedlars circulating mineral
• Important constituent of igneous rocks
• Large wading bird
• Rock producer's audience's axed on box
• Mineral cut, we hear, leading to minor dispute
• One leaving pitch to fight for a mineral