Blue is my favourite colour, as you can see by my braided blue hair. The Girl also has something blue on her head. She wears an headscarf because Vermeer painted her as a tronie (a character head) wearing exotic clothing. Ultramarine, the brilliant blue pigment that he used to paint the headscarf, also has an exotic back story.
‘Beyond the sea’ with ultramarine
Ultramarine is made from the brilliant blue mineral, lazurite, found in the semiprecious stone lapis lazuli. It’s incredible that almost all of the ultramarine used in the history of art comes from one place on earth: a few mines high in the slopes of what is now north-east Afghanistan. The name ‘ultramarine’ literally means ‘beyond the sea’. Some of the lapis was shipped to Europe from Central Asia in boats, but most of it came by land along a very old trade route: the Silk Road.
Mining the lapis, carrying it down the mountain and transporting it to Europe was just the start of the extremely laborious process needed to make good ultramarine. The steps involved in extracting the pigment from the rock are reconstructed in this video. The rarity of the raw materials and this time-consuming extraction process meant that ultramarine was the most expensive pigment available: more valuable than gold.
The shadow of the headscarf above her ear looks different now than it did when Vermeer painted it. The extent of possible degradation in the Girl’s headscarf is something we are researching as part of the Girl in the Spotlight project. Using the 3D digital microscope, we can inspect the surface in areas that seem to have degraded. With MA-XRPD we will learn more about the crystalline structure of the pigment, and how it has changed over time. Degradation of paint layers leads to new chemical compounds being formed on or close to the paint surface, altering its appearance. In the dark blue, MA-XRPD detected small amounts of two of these compounds: palmierite and weddellite.
Indigo: it’s in your jeans
In an earlier blog entry, I explained that the dark background around the Girl was originally a very dark green colour. On top of a black underlayer, Vermeer applied a green glaze containing weld (yellow) and indigo (dark blue).
Indigo is a dye made from the leaves of fermented indigo plants. The word ‘indigo’ means from ‘coming from India,’ although India was only one of the places where the plants grew. In the early 17th century, the Dutch East India Company (VOC) was formed. This caused a huge increase in the amount of indigo imported from India. But also, as part of the Atlantic trade, the Dutch also established indigo plantations in the tropics. A Dutch newspaper from the decades around when the Girl with a Pearl Earring was painted lists indigo among the cargo of Dutch boats coming from the West Indies. It was shipped along with tobacco, pepper, tea, nutmeg, sugar and ginger. Like these ‘spices’, indigo was usually sold in bulk as ‘cakes’, but could also be sold as smaller ‘lumps’.
