José Bonifácio D’ Andrada e Silva (1763-1838)
José Bonifácio D’ Andrada e Silva (1763-1838)
José Bonifácio D’ Andrada e Silva was a mineralogist, naturalist, miner, poet, commander, administrator, teacher, minister, tutor, among many other roles.
He was born on June 13, 1763, in Santos (Brazil), where he attended preparatory school with classes in grammar, rhetoric and philosophy. In 1783, he enrolled at the University of Coimbra in Legal Studies, Mathematics and Natural Philosophy.
In 1789, he was admitted to the Royal Academy of Sciences of Lisbon and, between 1790 and 1800, he made a scientific tour of Europe where he met René-Just Haüy, Abraham Gottlob Werner, Alexander von Humbolt and Friedrich Mohs. During this period, he discovered and described four new species of minerals: Cryolite, Spodumene, Petalite and Scapolite.
Returning to Portugal, in 1801 he occupied the chair of Metallurgy, created for him at the University of Coimbra. He was also the General Superintendent of Mines, Metals and Forests of the Kingdom, Director of the Royal Laboratory of the Mint of Lisbon and Administrator of the Coal Mines of Buarcos, in Cabo Mondego, and of the Iron Foundries of Figueiró dos Vinhos and Avelar. Later, he was appointed in charge of the Seedbeds in the Sandbanks of the Coasts and Superintendent of the Mondego River and Public Works of Coimbra.
He was part of the group of intellectuals who lived with Domenico Vandelli (his former teacher), and was the first to use the word technology in a scientific article, in 1815, in Portugal.
In 1819, he returned to Brazil, embraced politics and advocated the abolition of slavery, the incorporation of Indians into society, agrarian transformation, the preservation and renewal of forests, urban planning, sanitation and mineral exploration. He was Minister of Business and Minister of Foreign Affairs, and one of the main workers of Independence.
Due to political differences, at the end of 1823, José Bonifácio was arrested and sentenced to exile, near Bordeaux (France), along with his family. In 1829 he returned to Brazil and reconnected with the Emperor, who appointed him guardian of his children. He died on April 6, 1838 in Niterói, Brazil.
José Bonifácio D’ Andrada e Silva Mineral Gallery
Chemical composition is the basis of one of the most commonly used mineral classifications.
The organization of the mineral classes in the José Bonifácio D’ Andrada e Silva Mineral Gallery collection is established according to the main lines of the classical classifications proposed by Karl Hugo Strunz and James Dwight Dana in 1941 and 1959.
Minerals are homogeneous natural solid compounds with a defined but not fixed chemical composition, generally inorganic and with a crystalline structure, that is, an
ordered internal arrangement of atoms, ions or molecules. These arrangements are called unit cells, which when repeated several times in three dimensions, form a crystal.
There are more than 4,000 species of minerals. They are categorized by classes, defined by having the same anionic radical dominating their chemical formula (negative part of the basic mineral molecule: for example, chloride, phosphate, sulfate, silicate, etc.). They tend to occur in the same geological environment or in identical geological environments, causing them to have very similar characteristics.
The collection of minerals displayed here is divided into ten sets of mineral classes, namely: Native elements; Sulfides, Selenides, Tellurides and Sulfosalts; Halides; Oxides and Hydroxides; Carbonates, Nitrates, Selenates, Tellurates and Iodates; Borates; Sulfates, Chromates, Molybdates and Tungstates; Phosphates, Arsenates and Vanadates; Silicates; Organic substances.
1) Native elements
A class of minerals consisting of only one chemical element. Minerals that occur naturally as non-ionized elements, without the presence of anionic radicals. They are found in nature in a free form, without being combined with other elements.
2) Sulfides, Selenides, Tellurides and Sulfosalts
In sulfides, sulfur (anion S²⁻) is the main non-metallic element in their crystalline structure. In addition to the sulfides themselves, this class includes minerals composed of S, As, Se, Te, Sb and Bi with metals and metalloids, exhibiting chemical behavior similar to that of sulfur (S).
Sulfsalts are a type of sulfur mineral that has not undergone oxidation and is structurally different from sulfide. They can also be called double sulfides.
They are usually opaque minerals, with light colors and distinct colored streaks. Most ores belong to this category.
3) Halides
Halides are compounds characterized by the predominant presence of halogen anions, such as chloride (Cl-), bromide (Br-), fluoride (F-) and iodide (I-) ions. They have relatively low hardness and high melting points. In addition, they are considered poor conductors of heat and electricity when they are in a solid state.
4) Oxides and Hydroxides
The minerals in this group have in their structure combinations of metals with oxygen (oxides) or with oxygen and hydrogen (hydroxides) and it is from these that a large part of the metals used by Man are extracted. They have a relatively high density, although minerals in the hydroxide class generally have lower hardness and density compared to oxides.
5) Carbonates, Nitrates, Selenates, Tellurates and Iodates
Carbonates include minerals whose main anionic complex is (CO₃)²⁻. In the presence of hydrogen ions, they decompose into carbon dioxide and water.
Nitrates are a class whose main anion is the ionic group (NO₃)⁻. The salts formed by the reaction with nitric acid (HNO₃) have high solubility in water and are associated with recent geological formations.
Selenates, tellurates and iodates are respectively characterized by the anionic groups (SeO₄)²⁻, (TeO₄)²⁻ and (IO₃)⁻.
All of these minerals have low hardness, are translucent, weakly colored, have a non-metallic luster, a characteristic flavor, are biaxial and have a low melting point.
6) Borates
Borates are minerals whose main anion is the ionic group (BO3)³⁻ and their variants bind to metals, other anions and water molecules. Borates are salts, usually generated from boric acid (H3BO3) or polyboric acids.
Anhydrous borates, without water, are insoluble in water and often also in acids, and melt at high temperatures. Dry borates tend to hydrate gradually in aqueous environments at room temperature. Most of these minerals are transparent to translucent, with variable densities, and at lower temperatures, they tend to be replaced by carbonates.
7) Sulfates, Chromates, Molybdates and Tungstates
Sulfates have the central anion (SO4)2-. Stable and abundant sulfates are few and far between because they are very easily soluble in water.
In chromates, the main anion is the anionic group (CrO4)2-.
Sulfates and chromates are rare, transparent to translucent minerals with little hardness. They form in environments with high oxygen concentrations.
Molybdates and tungstates present the combination of the anionic groups (MoO4)2- and (WO4)2+ with metals. Although not very abundant, they constitute the main deposits of tungsten, lead and molybdenum ore.
8) Phosphates, Arsenates and Vanadates
This group of minerals has a trivalent group as its main anion, which can be (PO₄³⁻), (AsO₄³⁻) or (VO₄³⁻), giving rise to the subgroups known as phosphates, arsenates and vanadates. Although the presence of phosphorus (P), arsenic (As) and vanadium (V) in the Earth's crust is relatively small, this class encompasses a considerable variety of mineral species, being the second largest mineral group.
Most minerals in this class are rare or relatively rare. They generally have low to moderate hardness, variable density (with most being low) and are usually transparent to translucent.
9) Silicates
The silicate group is composed of minerals whose main anion is the group (SiO4)4- and its derivatives, linked to metals and other ions. The fundamental structure
is an oxygen tetrahedron with a silicon cation in the center, giving rise to various structural combinations.
Silicates are the most important mineral class, representing about 25% of known minerals and almost 40% of common minerals. They correspond to about 95% of the volume of the Earth's crust, of which 59.5% are feldspars, 16.8% are amphiboles and pyroxenes, 12% are quartz and 3.8% are micas.
10) Organic substances
Organic substances form complex molecules composed of carbon (C) and hydrogen (H) atoms. Examples of crystalline forms of organic substances include whewellite, Ca(C₂O₄)·H₂O, and mellite, Al₂C₆(COO)₆·16H₂O. Amber, in turn, is a fossil resin that is presented in an amorphous form, that is, it does not have a defined crystalline structure.
Crystal Systems
The vast majority of minerals have a crystalline structure, that is, they form crystals. Only 0.3% do not have an ordered arrangement of atoms that characterizes crystals, which is why they are called amorphous.
Crystals are classified according to the geometric organization of their atoms, the relationship of dimensions and angles between the crystallographic axes.
There are seven crystal systems (CS): cubic, tetragonal, hexagonal, trigonal, orthorhombic, monoclinic and triclinic.
The cubic system has three crystallographic axes of the same size and mutually perpendicular.
The tetragonal system has two axes of the same length and one different length, all perpendicular to each other.
The hexagonal system has three horizontal axes of the same length, separated by angles of 120º, and a vertical axis with different length and senary symmetry.
The trigonal system has three horizontal axes of the same length, separated by angles of 120°, and a vertical axis of different length and ternary symmetry.
The orthorhombic system has three crystallographic axes that are mutually perpendicular, but each with a different length.
The monoclinic system consists of three crystallographic axes of different lengths, with two angles of 90° and one distinct angle.
The triclinic system has all the crystallographic axes and all the angles different from each other.
Andradite Ca3Fe2Si3O12
Andradite is a mineral of the garnet group and was described in 1868 by James Dwight Dana in honor of José Bonifácio de Andrada e Silva (1763-1838). A disciple of Domenico Vandelli, he was a professor of Metallurgy at the University of Coimbra and also distinguished himself as a mineralogist. In 1800, he discovered a yellowish-gray garnet from a mine near Drammen, Buskerud, Norway, which he named allochroite (Ca3Fe3+2Si3O12), which Dana later defined as a variety of andradite in 1868.
