Aside from the retired ballerina, the only thing I put in my jewellery box was a blue copper sulphate crystal I’d made in science class. Other than its stunning shade of blue, it was not a particularly pretty situation, and, as it hadn’t occurred to me to cut the string I’d grown it off, it looked more like a jagged little tampon than it did a precious stone. But it was still the closest thing I had to jewellery until I bought myself a necklace.

