Jewellery expert and author Joanna Hardy chooses her highlights from the upcoming jewellery sale at Christie's auction house in London:

Previewing the lots in Christie's South Kensington jewellery sale on 20 March, it struck me that there is lots of colour in this particular auction. From a magnificent Cartier necklace - one of my favourite pieces up for auction - and coral Van Cleef & Arpels brooch to a vari-coloured beryl and diamond necklace, colourful hues were everywhere.

I love lot 123, a contemporary suite of multi-gem and diamond 'Meli Melo' jewellery by Cartier. Fun and unique, the design of the necklace and earrings are not typical of the famous French jeweller, incorporating pink tourmaline, aquamarine, iolite, garnet, chalcedony and moonstone with brilliant-cut diamond detail. Signed Cartier, the suite comes with maker's pouches.

Lot 93 is a vanity case, circa 1940, set with a cabochon ruby and signed Boucheron Paris. Vanity cases are often overlooked by collectors, but this is a a real treasure. Typical of the Boucheron style of the 1940s, it has a mirrored and pierced foliate gold-plated cover, engraved with birds and foliage, and opens to reveal compartments with hinged lids. 

The auction takes place at 10.30am on Wednesday 20 March at Christie's Saleroom, 85 Old Brompton Road, London.