When you go into a bookshop, which department do you head straight to? The one with the sofas. My favourite bookshops are independent ones with chairs in them, and people who love books, and a bit of organised chaos. A few weeks ago I was in Shakespeare & Co in Paris with a few hours to spare. I went to the top floor (which has a cat, several sofas, a little desk with typewriter that Hemingway would have loved no doubt) and I found a second hand version of Vita Sackville West’s Thirty Clocks Strike the Hour. And I read the title story and was transported then to the Boulevard des Italiens where her great-grandmother had a vast corner house with twenty windows on the boulevard and where, one night, the young Vita hid in shadows and watched her grandmother, walk slowly through all those grand rooms until she reached one with thirty clocks… When I left the shop a couple of hours later I had moved into another dimension. I’ll go to any bit of any bookshop to find the books (which could be in science or music or fiction or art or memoir or travel) that will do that.

Looking back, which experiences, jobs and personality traits do you think have really helped you? I was studying journalism in an intensive three month course in the early 1990s when a fellow student asked “if you could write for any magazine or newspaper anywhere, where would it be?” I answered immediately “The South China Morning Post in Hong Kong in the run up to the handover in 1997”. I had not been to Hong Kong nor had I ever read the SCMP but it seemed the most romantic thing possible. So I applied to work as an intern. And that job which became permanent and grew to working on news, features and then as arts editor, in Hong Kong for what turned out to be 12 years, was one of the happiest times of my life. And made me a better journalist and writer.

What inspired you to start writing? When I was six, I was given a box of Caran D’ache pencils for my birthday. But I already had one, so I swapped it with a schoolfriend who had a spare copy of The Magician’s Nephew. That night I read it under my blanket and was both terrified and entranced by how CS Lewis created an image of pools in which worlds are being created. I was only a small child but I understood then, that night, how writers can be magicians. I became an avid reader and ached to be a writer. My schoolfriend, incidentally, became an artist. 

Was there a particularly hard colour or pigment to research in Colour? I knew that if this was going to work as a book there were some pigments I just had to travel to the source of. I had to visit a cochineal farm (which was my first journey, before I was commissioned by a publisher). I also had to go to remote parts of northern and central Australia to research the traditional aboriginal uses of ochre, and above all I had to go to the lapis mines of Afghanistan to find the source of Michelangelo’s blue. The first two journeys had their challenges and delights (you can read about them in the book) but the blue… I really did think for a while that I might not get there. The Taliban were running the country and it was almost impossible to get to Afghanistan and not safe. But I was determined, as without it, I wouldn’t have felt I had produced a book that did what I set out to do. I went first to Kabul (by absolute coincidence a friend had met a handsome Italian doctor riding a motorbike on the Silk Road… he was working in Afghanistan and he had offered to get her and a friend a visa to visit) – that’s how I got to Bamiyan, just months before those beautiful painted Buddhas were blown up. But Google wasn’t as good then as it is now, and when I got there I realised the blue mountains were on the other side of the firing line. Then I flew to Hawaii because I thought a gem dealer who lived there might help me get across the Pakistan border into the northwest area, where the lapis lazuli was. But he couldn’t. At last, thanks to friends in the UN, I did get there (paying my way, obviously), and the jeep broke down. The four people I was with (two journalists, again coincidentally going to the mines for a story for Time Magazine, Abdullah my translator and the driver) were really cross but I was delighted as it had become a proper journey, with real obstacles. And so finally, there I was, halfway up a mountain, ducking my head to walk along the mines where men for 6,000 years or more had risked their lives to look for blue.

Was there a particularly hard gem to research in Jewels: a Secret History? Similarly, for Jewels I knew that I just had to get to see the ruby mines in Burma… which were hard to get to. I ended up flying to Arizona to the gem fair, which is where a dealer gave me the clue (about the government travel agency which might, just might, take me) which enabled me to go. Emeralds had their challenges too: I decided not to go to Colombia – it was really dangerous to go to those regions, and the stories were well documented – but instead to follow up a lead from a 19^th century gem dealer who had gone to find the lost emerald mines of Cleopatra in the desert. Curiously while they were no longer lost, they are scarcely visited (a shame) and it was really hard (took months and lots of meetings and false leads) to find someone who would guide me and drive there to those abandoned Roman times. I had this romantic idea of going by camel but I was told strictly that it would take weeks and in the end it was two jeeps (you had to have two because it was so remote). They told me in advance that they wouldn’t go into the mines though: the Bedouin believed they were haunted, and the western guide hated enclosed spaces. As does my husband. So, having had an emergency lesson in caving from a speleologist in Derbyshire a few days before, I ended up climbing down alone, feet first, through tiny tunnels where men worked 2,000 years before. And praying that a piece of string and some spare torch batteries were going to be enough to stop me from getting lost or falling or being stung by a scorpion. Birds and bats flew past in surprise. And at one point I looked down and there was a tiny, imperfect, but unmistakeably green emerald crystal.

Which are your favourite images in these books? In Colour there’s an image of the Papunya Tula artists at Papunya, Australia in the early 1970s, standing in front of a huge corrugated iron shed, holding paintings. The right to use that photo was given to me by Geoffrey Bardon, who as a young man in 1971 went to teach art to Aboriginal children at Papunya, and ended up giving acrylics to the old men, who painted their Dreamings with these new colours, in new patterns, and thus started the Central Desert painting movement. Geoffrey told me the story over an evening I spent with him and his wife and after dinner he and I sat in his garden. He had Parkinson’s so it was hard for him to speak and he had to keep pausing and resting. And it was a hard story too: of betrayal and threats by others, and his own nervous breakdown, as well as being about how some Aboriginal people, displaced from their land, created astonishing modern artworks and were able at least to have some kind of financial independence. When I see that picture I think of looking at the eucalypts waving in the breeze as the sun set, and as Geoffrey, who died a few years ago, struggled to tell his story.

What was one of the best things that happened because of these books? Lots of lovely things have happened; I’ve been to some terrific books festivals, and met fascinating people. I was asked a couple of years ago by the Getty Museum in Los Angeles to write a very different book about colours, called The Brilliant History of Color in Art (it came out in November 2014) designed initially for teenagers although we wanted it to be interesting for anyone who likes art. So I spent five weeks in California as a visiting scholar. I used to walk up and down the hill to the museum, which was exhilarating in itself. At twilight you can see the cars on the freeway far beneath: red lights going one way, white lights the other. Every day I spent at least an hour in the galleries, with a borrowed magnifying glass, looking in depth at their collection of European art. I talked to some terrific experts, got to look at the special collections in the library, and found all sorts of new and exciting things about colours, meaning it is definitely not a reworking of my old research. I always spend far too much time collecting more information than I could possibly use. Like how to date Sevres porcelain by the colours used. I could do a whole chart on that. And maybe one day I will.

Read the review of ‘Colour; Travels Through the Paintbox’ here and ‘Jewels; A Secret History’ here.