Angela made the unusual royal revelation in her new book The Other Side of the Coin: The Queen, The Dresser and the Wardrobe.
“A little gin and water come in handy to give the diamonds extra sparkle - just don’t tell the jeweller!” Angela wrote.
While Her Majesty’s jewels are generally professionally cleaned, the style advisor added if need be the trusty hack works like a charm every time.
“The Queen’s jeweller will give the stones a deep clean when necessary, so for me it’s just a matter of a quick polish and they’re sparkling once more,” she said.
The handy little tip is just one of several insider revelations from Angela’s book, which also revealed the Queen shares Kate Middleton’s thrifty nature.
According to Angela, the monarch loves nothing more than finding a bargain when it comes to her fabric selections.
In an excerpt from her new book, The Other Side of the Coin: The Queen, the Dresser and the Wardrobe, shared with Hello magazine, Angela said she is forever rummaging through the “bargain basket”.
The dressmaker said that the Queen is quite partial to a bright pop of colour, which is evident by her wardrobe, so she is forever looking for “vibrant fabrics”.