#I'm dedicating part of my winter break to research minerals and crystals just because :)

[sunsolii]

Napoleon's Marshals and their Birthstones Part 1

This is a three-part series where I'll be listing the birthstones of all 26 marshals. Part one will cover months January-April, the next post will cover March-August and the last post will cover the remaining 4 months. I'll mainly be focusing on the gemstone's physical and chemical properties as well as writing "short" facts about each gemstone. Before starting the list, I'll provide the definitions of some terms that will be used through the post.

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Mineral: A naturally occurring solid which contains a crystalline structure that is made up of a single native element or multiple chemical compounds.

Mohs Scale: A scale system used to measure the scratch resistance of a mineral ranging from 1 (softest) to 10 (hardest). This is done by scratching a mineral with another mineral or with another object like a penny or nail.

Cleavage: The way in which a mineral breaks along the softest plane. Classification of a cleavage ranges from perfect, good, poor, indistinct, to none. A mineral can have a basal, prismatic, cubic, rhomboherdal, octahedral, or dodecahedral cleavage.

Fracture: The texture or shape of a mineral's surface. Some types of fractures are described as conchoidal (ripples), earthy (resembles broken soil), hackly (jagged fractures), uneven, and splintery (resembles splinters).

Luster: The way which light reflects off of a mineral. Minerals can have vitreous (glassy), dull (earthy), adamantine (shiny), greasy, silky, metallic, non-metallic, pearly, resinous, or waxy lusters.

Streak: The color of the powder left behind by a mineral when it is scratched on a piece of unglazed porcelain. The color of the powder is usually different from the mineral's color.

Now, onto the list!!

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Garnet (January)

Marshals-Ney and Bernadotte

Type: Mineral

Group: Silicate (SiO₄)₃

Color: red, orange, pink, green, yellow blue (rare)

Cleavage: Indistict

Fracture: Conchoidal to uneven

Mohs Scale: 6.5-7.5

Luster: Vitreous

Streak: White

Fun Fact: Garnet is its own family that contains six main species divided into two groups: pyrope, almandine, and spessartine species, which are part of the aluminum group (aluminum is present in its structure). Colors in the Aluminum group range from red to pink; these are the garnet species people think of when looking for jewelry. When pyrope is mixed with almandine, it creates rhodolite, and when mixed with spessartine, it creates malaya. Grossular, uvarovite, and andradite species are part of the calcium group (Calcium is present in structure) and are composed of green to yellow garnet. Uvarovite is the rarest of the calcium group because it grows in small chunks, making it hard to work with when making it into a gemstone.

Amethyst (February)

Marshals- Mortier

Type: Mineral

Group: Silicate (SiO₂)

Color: Purple to Violet

Cleavage: Indistict to none

Fracture: Conchoidal

Mohs Scale: 7

Luster: Vitreous

Streak: White

Fun Fact: Amethyst is part of the quartz family and it used to be part of the cardinal or most valuable gemstones, along with diamonds, rubies, and sapphires, because it was available in small amounts. Its value dropped after large deposits were discovered in Brazil during the 18th century, making it one of the more affordable gemstones.

Aquamarine (March)

Marshals- Brune, Murat, Soult, Suchet

Type: Mineral

Group: Beryl (Be₃Al₂Si₆O₁₈)

Color: Pale blue, light green, bluish-green, sometimes yellow

Cleavage: Indisticnt to none

Fracture: Conchoidal to uneven

Mohs Scale: 7.5-8

Luster: Vitreous

Streak: White

Fun Fact: Aquamarine got its name because its color resembles the sea. It contains small traces of iron, which (depending on the oxidation state) can change its bluish color to green or yellow. These oxidation states are ferrous iron, which gives Aquamarine its blue color, and ferric iron, which gives it a greenish/yellowish color. Heating the mineral removes the greenish color to restore its blue color[1]. Aquamarine also has weak to moderate flourescent properties under UV light [2].

Diamond (April)

Marshals- Jourdan, Lannes, Oudinot, and Saint-Cyr

Type: Mineral

Group: Native mineral (Carbon (C))

Color: Yellow, brown, gray, white, colorless,

Cleavage: Octahedral, Perfect on all sides

Fracture: Uneven

Mohs Scale: 10

Luster: Adamantine

Steak: Colorless

Fun Facts: Diamonds are formed within the Earth's mantle when carbon-rich materials or carbon dioxide are subjected to extreme temperatures and pressure. It reaches the surface via volcanic eruption and gets trapped inside igneous rocks after the magma cools off. The formation of diamonds takes thousands of years, contributing to their high value [3]. Diamonds seen as potential gemstones have little to no impurities or foreign objects within their structure. In contrast, diamonds with high impurities, irregular shapes, and defects are used in commercial industries due to their durability and hardness. Diamonds are the hardest minerals, and are very difficult to scratch or break, but it's not impossible to do so. They also has a high dispersion of white light that creates a rainbow-like effects, also known as 'fire.[4]'

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Sources

Garnet: King, H. M. (n.d.). Garnet. geology. https://geology.com/minerals/garnet.shtml

Amethyst: Geary, T.F.; Whalen, D. (2008). The Illustrated Bead Bible: Terms, Tips & Techniques. Sterling Pub. p. 69.

Aquamarine: [1]King, H. M. (n.d.). Aquamarine. geology. https://geology.com/gemstones/aquamarine/

[2]MAT, M. (2023, June 3). Aquamarine: Properties, formation, occurrence " Gemstone. Geology Science. https://geologyscience.com/gemstone/aquamarine/?amp

Diamond: [4]King, H. M. (n.d.). Diamond. geology. https://geology.com/minerals/diamond.shtml

[3]MAT, M. (2023, September 25). Diamond: Properties, formation, occurrence, deposits. Geology Science. https://geologyscience.com/minerals/diamond/