Call me a hopelessly stereotypical girl fascinated by sparkly things, but two of my favourite galleries in the Museum are the Earth's Treasury and the Minerals Gallery.

Yes, they're both filled with pretty crystals, gems and minerals, but I love them also because they're a testament to the beauty of our planet, and, in the case of the Minerals Gallery, it harks back to the inception of this Museum, this cathedral to nature, with its original 1880s layout and oak cabinets.

Top: the Minerals Gallery pictured in the 1920s (left) and today (right).

Bottom: a beautiful array of gemstones in the Earth's Treasury.

As I've mentioned before, I have a particular soft spot for amethyst. This is mostly to do with the fact that I like the colour purple, and not necessarily because of the particular properties ascribed to the stone (that it 'wetteths the witt', makes a person calm and fruitful, and even protects against drunkenness). However, I do find the uses of minerals and the belief in their alleged attributes (subscribed to from as early as 200BC until at least the 1750s) a fascinating topic.

In pre-Englightenment times, some minerals, in addition to their use as decorative items and the manufacture of pigments, were credited with 'magico-medicinal properties'.

I recently dropped into a Museum Members' event to hear Dr Christopher Duffin, scientific associate in the Earth Sciences Department at the Museum, discuss the subject:

The intense colours and durability of gems and semi-precious stones, as well as the shapes of certain fossils or 'figured stones' led to the assumption that they could cure certain diseases by sympathetic magic, or similia similibus curantur (like cures like). A good mineral collection could benefit its owner in a multitude of ways.

Without giving away the most extraordinary claims and spoiling Dr Duffin's event for future attendees, let me tell you about just a few of the qualities attributed to certain gemstones and the reasons why:

• Lapis lazuli and azurite: used to treat melancholy (brilliant blue colour - makes you feel happy)
• Nephrite jade: used to treat kidney conditions (nephrite - nephritic syndrome)
• Haematite: used to treat conditions involved with blood (haematite - haemorrhage, etc)
• Magnetite: could draw out arrows and heal battlefield wounds (magnetite - magnetic properties)
• Amber: used to treat urogenital problems (yellow colour - urine)
• Almandine garnet: could strengthen the heart and help with circulation (red colour - heart and blood)

It might be hard to imagine today, with the hindsight of empirical science, that such theories could be considered credible, but Dr Duffin says:

(In pre-Enlightened times) everything was seen against the backdrop of good and evil, and that everything the planet had been provided with - the plants, the rocks - had been put there for a purpose to help mankind.

Almandine garnet: for the benefit of the heart and the circulatory system.