Possible Clues:

• Silence engulfing a superior part of Oxford? It's a gloomy place
• Building with a tomb
• Gold only to be used in mother's tomb
• Area in V and A, say, containing most of ancient tomb
• Mummy with inscribed gold fish in burial chamber
• Gold one found inside quiet tomb
• Large tomb, parent bagging a posh one
• Mum went around clinging to gold, alone in a burial chamber
• Usual memo recirculated was a great wonder
• Endless haul only found in quiet tomb