The exhibition “Trésors de la terre" (Treasures of the Earth) presents nearly 600 of the most remarkable pieces in the Museum's collection, including some twenty giant crystals. The visit circuit through the exhibition was developed with the help of the Museum's scientists, and answers many specific questions, such as: What exactly are minerals? Where do they come from? How do they grow?
on May 19
Galerie de Minéralogie et Géologie
36 rue Geoffroy Saint-Hilaire
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The Mineralogy and Geology Gallery
The giant crystals of the Museum
At the heart of the exhibition Trésors de la Terre, giant crystals offer a breathtaking introduction to the subject.
Selected by the mineralogists of the Muséum national d'Histoire Naturelle (National Museum of Natural History), eighteen of the eighty giant crystals from the Ilia Deleff collection, acquired in 1982, are exhibited on a podium in the centre of the main hall. Among these giant crystals, several imposing quartzes weighing 2 or 3 tons stand alongside large geodes containing thousands of small amethyst crystals.
A film explores the epic story of these crystals, from their discovery in Brazil, to their current home, not to mention their first presentation to the public at the Museum in 1983.
Discover the mineral world
The first stages of the visit circuit lead visitors through the world of rocks and minerals, not always well-known but endlessly fascinating. What is a mineral? How did the minerals form over time? How do scientists classify them? All these fundamental questions are answered in an introduction to the discovery of the mineral world.
A large timeline gives an overview of the various events that led to the formation of minerals, from the birth of the solar system to today.
In the showcase, twenty or so specimens represent the ten major classes of the Strunz mineral classification. This classification, based on the chemical composition of minerals, is today the system most commonly used by scientists.
An infinity of shapes, a multitude of colours and lights!
The collection of minerals presented in the « Treasures of the Earth » exhibition is remarkable for its shapes and colours. It sheds light on the formation of crystals and the origin of their diversity in nature.
For the same chemical composition, a solid will crystallise in many different ways depending on the depth of its formation in the earth's crust, the temperature and pressure prevailing at the site of its formation, the abundance and nature of the fluids from which it is formed, and the space available for it to grow. The influence of some of these mechanisms is presented in an animated film.
The structure of a crystal is determined by an equilibrium point between the diameter of its atoms and their electrical charges. The result is an essential feature, known as symmetry, which in turn defines the way the atoms assemble into crystalline lattices. Among the most astonishing specimens you will find in our collections are twenty giant crystals from Brazil. You'll also see the Laurent Fluorite, discovered in 2006 in the Mont Blanc massif, and which is the first entirely natural object ever to be classified a "work of art of major heritage interest."
Minerals are endowed with a wonderful variety of colours — the greens of malachite and dioptase, the blues of topaz and azurite, the reds of ruby and vanadinite, the yellow of mimetite... You will also discover that a single mineral species can adopt several shades, with a series of samples of fluorite in yellow, green, blue, pink, red, black, and perfectly colourless. An animated film explains this chromatic diversity, while another display shows how pigments known since the dawn of time, such as ochre, haematite and lapis lazuli, are extracted from raw minerals.
The brightness and transparency of a mineral depend on how its structure interacts with light. Depending on their organisation, the atomic lattice may either reflect light waves or allow them to pass. A display shows the phenomena of pleochroism, in which the colour of a crystal changes with the angle of view. The fluorescence of certain minerals is revealed when they are illuminated by ultraviolet rays.
The world of gemstones, art and precious stones
Here, the Museum presents some of the most valuable objects in its collection. Some have belonged to eminent figures, such as a diamond-encrusted snuffbox belonging to Alexander I, or the Grand Sapphire of Louis XIV. Others wear their natural, unadorned beauty.
Semi-precious and precious stones
The most ancient use of precious stones was practical - their hardness made them useful for sharpening tools. Then they were believed to hold magical or healing powers. Once man learned how to cut stones, they were transformed into objects of art and envy. Known since antiquity in Asia, the art of faceting was only practised in Europe from the fifteenth century onwards. A number of display cases hold different cut or manufactured stones, alongside raw, uncut minerals for comparison. A multimedia terminal invites visitors to discover how the stones are cut, the importance of their hardness, and the geographical origin of the stones on display.
The crown jewels
One magnificent showcase holds gems from the historical royal and imperial collections, donated to the Muséum national d'Histoire naturelle. Among these jewels are the Saint-Louis Emerald, the Grand Sapphire of Louis XIV, an evocation of the pink topaz Grand Parure of Empress Marie-Louise, and the Great Opal of Charles X. Another installation is dedicated to the story of the Great Blue Diamond of Louis XIV, stolen during the French Revolution and then recut to become the legendary "Hope" diamond, today preserved at the Smithsonian Institution in Washington DC. The central piece of this reconstruction is the lead casting of the Louis XIV diamond, rediscovered in 2007 in the Museum's collections, which proved the relationship.
Precious metals and ornamental stones
In nature, gold, silver and platinum exist in the form of flakes, dendrites, nuggets or crystals. In their raw state, these precious metals are soft and easy to work with. Many other minerals are used in jewellery and the decorative arts. Ornamental stones such as jasper, malachite and lapis lazuli can be shaped into objects or cut into fragments with precise outlines for the art of stone marquetry. Two exhibited Florentine tables are decorated with highly technical flower and bird patterns, a tour de force of the art. Alongside them you will see a number of richly decorated cups, most of which belonged to Louis XIV.
The museum collection and research
The 130,000 specimens that make up the Museum's mineralogy collection make it one of the world's largest. Five dedicated missions are directed by the Muséum national d'Histoire naturelle — the conservation and enrichment of the collections, scientific research, teaching, a service of expertise, and the dissemination of knowledge.
In this part of the exhibition, a timeline presents some sixty specimens of minerals in the chronological order they joined the collection, the first being those of the King's own medicine chest, from 1626. The specimens are displayed according to a timeline of historical events — expeditions, gifts to the museum, legacies, donations, the work of great scientists and the Total's patronage, each with a story of their arrival in the museum collection.
The collection of azurites, built over time thanks to the generosity of donors and scientists, is presented with particular pride. Reading through the timeline, visitors discover the most important minerals acquired in recent years. A touch screen gives details of research currently being conducted by scientists at the Museum.
The world of meteorites
Fragments of celestial bodies sailing the heavens, and fallen to Earth, meteorites provide researchers with invaluable information about the birth and evolution of the solar system.
The Muséum national d'Histoire naturelle has one of the largest collections of meteorites in the world. It comprises some 4,000 samples, from newer discoveries to pieces known to the ancients Among them are Ensisheim, which fell to Earth in Alsace in November 1492, and fragments of the Chelyabinsk meteor, which landed in Russia in February 2013.
They are a source of information for scientists seeking to understand how the Sun and the planets that surround it first formed and then evolved.
Primitive meteorites (chondrites) are fragments of rock bodies that formed at the same time as the Sun. They provide information on the origin of the solar system and help to determine its age.
Differentiated meteorites are witnesses to the evolution of the planets. Unlike primitive meteorites, they have followed a similar evolution to that of the inner planets of the solar system. The exhibition also features meteorites from Mars and the Moon.
Impact craters are the scars of collisions between bodies in the Solar System. Craters cover the surface of the Moon and other celestial bodies with no protective atmosphere. The craters that once marked the Earth have tended to fade away as a result of erosion and plate tectonics. Resulting from a sudden release of energy, the crater cavity often has a diameter 20 to 30 times greater than that of the meteorite that created it. Thus, it is estimated that Meteor Crater in Arizona, USA, with a diameter of 1.2 km, was formed by an object 40 m in diameter, of which only a few fragments, known collectively as the Canyon Diablo meteorites, survived the explosion.