Parisian Blue—the new fashionable dye

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Newsletter of the University of Lille - What's new in science?

The new Parisian dye: fashionable and state-of-the-art

Chemical research is a top priority in France, and His Majesty counts on all of you, the best students of our universities, to pursue these studies for the glory of France and the supremacy of our industry and army.
In addition to its more serious aspects, chemistry can also be a fun and lucrative subject of research, as best exemplified by the recent invention of a new blue dye to replace expensive ultramarine.

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Chemistry

Blue dyes

Blue dyes can be made thanks to different prime elements: cobalt, nickel, and now also aluminium. Traditionally, they were made by crushing rocks and diluting them. The best of all blue, ultramarine, is made with lapis lazuli, a very expensive rock imported from Afghanistan. In 1847, Prof Guimet of the University of Paris invented a synthetic process to recreate the dye for a price a thousand time lesser.

Composition

This new "Parisian blue" is in fact an aluminosilicate zeolite with a sodalite structure. Explanation:

Zeolite
A compound made of silicon (Si), aluminium (Al), and oxygen (O).
This specific aluminosilicate is (Na,Ca)₈(AlSiO₄)₆S₂

Sodalite
Structure made of interconnected cages of aluminosilicate.
Each cage has a micro pore in its middle containing either:

the negative polysulphide ion S₃^-

the positive sodium ion Na⁺

It is the polysulphide that gives the compound its magnificent blue colour.

Magic

The presece of aluminium also confers interesting properties to the objects painted with this dye. Since aluminium is a reflector of magic, used in shields and armours, clothes died with this Parisian blue protect against any magic cast on them. Perfect for their owner, less good for their enchanting and cleansing.
Luckily, while the dye is less expensive than lapis lazuli, its price is still high enough to ensure that their owner will be able to pay for a full alchemical treatment of the fabric before it is dyed and for their servants to painstakingly clean them by hand.

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Importance

Rivalry

Prof Lecoeuvre

The field of chemistry is animated by a fierce competition between Paris' top chemist and the inventor of this new dye, Prof. Guimet, and Lille's Prof. Michel Lecoeuvre, the discoverer of a new prime element, iridium.

Impact of iridium

This should normally have been a clear victory for Lille, as iridium as a very high magic-conductivity, which makes it perfect for design new, more efficient weapons for our elite soldiers and lone ace division. Unfortunately, iridium has proven very difficult to find: the mines of Lherz in the Pyrénnées only have small nuggets and have often been inaccessible in the past 50 years during the wars with Spain.

Impact of Parisian blue

In contrast, Parisian blue is extremely popular all over Europe and is thus providing Prof. Guimet with huge funds with which to pursue his research into new elements, thus eliminating the necessity and stress of participating in funding competitions.

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We therefore count on all of you to help Lille beat those arrogant Parisians once and for all!