A private gemstone tour

To celebrate the return of post-pandemic, in-person events, we were delighted to host an exclusive, behind-the-scenes tour of the most magical and fascinating gemstones and minerals at the Natural History Museum, London.

Led by curators Robin Hansen (Mineralogy and Gemology) and Andrea Hart (Library Special Collections) the tour began in the atmospheric Earth’s Treasury gallery, surrounded by beautifully up-lit display cases containing a vast variety of minerals and rocks, from large geodes to extremely tiny cut gemstones. Guests (including jewellery journalists Annabel Davidson, Rachel Garrahan, Jess Diamond and Heidi Garnet of Gem X) were shown a variety highlights from the gallery, most notably a new paraiba tourmaline specimen which is yet to be put out on display. The specimen contains three tourmaline crystals growing in white quartz. Robin explained that the original specimen, when purchased, only hinted at what might have laid beneath the quartz. Careful excavation revealed the true extent of the paraiba encased in the quartz, resulting in it becoming a very special object.

From there, guests moved on to the spectacular Minerals Gallery, a vast space of neatly arranged glass cabinets showcasing the extensive collection of minerals and gemstones in the Museum’s possession. Being out of hours, we were able to admire their star specimen – an enormous blue topaz stone of 9,381 carats – to ourself before the Museum opened to the public. Known as the Ostro stone, this Brazilian topaz weighs in at approximately two kilogrammes and is a deep royal blue colour, much like a mid-blue sapphire.

Other highlights from this gallery included a number of carved agate objects, including delicate bowls, miniature cups and spoons; an extremely rare selection of topaz crystals that were housed in their own custom-made, crystal-shaped boxes; a boulder opal in the shape of a heart; and some impressive triangle tourmaline slices.

Before moving to the Anning Rooms we explored The Vault, home to some of the Museum’s most unique and valuable mineralogy and gemology specimens. Here we enjoyed listening to the story of the Winchcombe meteorite and the magical tale of the Aurora Pyramid of Hope, a collection of 296 coloured diamonds amassed by a private collector in New York. The Museum believes this to be the most rare and extensive collection of coloured diamonds in the world.

The final stop on our behind-the-scenes tour was a show and tell in the Museum’s Anning Rooms. Andrea showed our guests some of the most important books and folios on minerals and gems in the Museum’s collection, including one that illustrated hundreds of specimens in curiosity cabinet form. We were also able to handle some gemstone samples, such as emerald crystals and a box of pink spinels which inspired Farrow & Balls’ Nature Collection.

A massive and heartfelt thanks to Andrea and Robin and the rest of the team at the Natural History Museum for making this private tour possible. It was the best way to start any Monday morning.