Introduction to Mineralogy

Introduction to Mineralogy

• Mineralogy is the study of the physical and chemical properties of natural, solid, crystalline materials.

• It is a core discipline within earth sciences.

• It branches into physical mineralogy, chemical mineralogy, environmental mineralogy, and descriptive mineralogy.

History of Mineralogy

• Stone Age:
  • Prospecting methods: fork stick and trenching.
  • Flint tools: made from silica and chert.
• Early Civilizations:
  • Pigments: red hematite and black manganese oxide used in cave paintings.
  • Tomb paintings in Nile Valley, Egypt: depicted artisans working with malachite, precious metals, smelting ores, and making lapis lazuli and emerald gems.
• Bronze age:
  • It began around 6000 years ago and involved the Copper age, Bronze age, and Iron age.
  • Minerals were used mainly for ornaments and jewelry.
  • The discovery of smelting: extracting metal from ore by heating and melting.
• Ancient Greek Philosophers (300 BC to 200 AD):
  • Aristotle: wrote "Meteorologica", suggesting that all substances are composed of water, air, earth, and fire.
  • Theophrastus: authored the first book on mineralogy.
  • Pliny: wrote "Natural Historia," documenting the mineralogical knowledge of his era.
• 1556: Georgius Agricola
  • A German physician who published "De Re Metallica".
  • This book gave detailed accounts of mining practices during the time.
  • Marks the emergence of mineralogy as a science.
• 1780: Carangeot
  • He invented the contact goniometer, which is utilized for measuring interfacial angles.
• 1783: Jean-Baptiste L. Rome de l'Isle
  • He made angular measurements on crystals, verifying Steno's work.
  • He developed the Law of Constancy of Interfacial Angles.
• 1784-1801: Rene J. Hauy
  • He demonstrated that crystals are formed by stacking identical small building blocks called "integral molecules".
  • He formulated the theory of rational indices for crystal faces through his study of hundreds of crystals.
• 1809: William Wollaston
  • He invented the reflecting goniometer, enabling more accurate measurements of crystal face positions.
  • This turned crystallography into a precise science.
• 1779-1848: Jons Jacob Berzelius:
  • He and his students studied the chemistry of minerals.
  • They developed the principles for the current chemical classification of minerals.
• 1828: William Nicol
  • He invented the Nicol prism, the first device to create plane-polarized light.
• 1912: Max Von Laue
  • He conducted an experiment with Friedrich and Knipping, proving that crystals diffract X-rays.
  • He established the ordered arrangement of atoms in crystalline materials.
• Early 1960s: Invention of the Electron Microprobe
  • It enabled the study of mineral chemistry at a micro-scale.
  • It is now used to analyze the chemistry of minerals, synthetic compounds, and glasses.
  • It provides multi-element analyses of solid materials, even as small as one micrometer (0.001 mm).
• Early 1970s: Invention of Electron Beam Instrument
  • It could magnify the internal structure of minerals millions of times.
  • High-Resolution Transmission Electron Microscope (HRTEM) allows the study of crystalline materials at near atomic resolution.

Naming of Minerals

• Minerals are often classified based on their major chemical component (anion or anion-complex).
• Minerals may be named after localities, public figures, mineralogists, or various other subjects.

Mineral Classification (7 Major Groups)

• Native Element
• Sulfides
• Oxides
• Carbonates
• Sulfates
• Halides
• Silicates

Examples of Mineral Names

• Albite: from the Latin "albus" meaning white.
• Chromite: named due to its high chromium content.
• Magnetite: named for its magnetic properties.
• Luzonite: named after Luzon, the largest island in the Philippines, where it was discovered.
• Cummingtonite: named after Cummington, Massachusetts, USA, where it was first found.

Mineral Definition

• A mineral is a naturally occurring solid with a highly ordered atomic arrangement and a definite (but not generally fixed) chemical composition. It is usually formed by inorganic processes.

• Naturally occurring: formed by natural processes, not by humans in laboratories.

• Inorganic process: Traditionally defined as inorganic, but now often includes compounds formed by organic processes.

• Homogeneous solid: consists of a single substance not subdivisible into simpler chemical compounds.

• Definite (but not generally fixed) chemical composition: expressed by a specific chemical formula with possible impurities.

• Ordered internal structure: atoms are arranged in a geometric pattern called crystal structure.

Mineraloid

• Has mineral-like chemistry and occurrence, but lacks an ordered atomic arrangement.

Gems

• Minerals that are beautiful enough to be used in jewelry.
• Qualifications: Beauty, Durability, Rarity, Vagary of fashion.

Mineral Stats

• Internation Minelalogical Association (IMA) recognizes 5,955 official mineral species (as of July 2023).
• ~30 are common minerals.
• ~10 are rock-forming minerals.

Uses of Minerals

• Minerals are essential for various industries and human needs, including building, technology, and health.

Importance of Minerals

• The saying "If it can't be grown, then it has to be mined" highlights the vital role of minerals in society.

Mineral Cup 2023

• A competition celebrating minerals, held annually.

Explore the fascinating world of mineralogy, which investigates the physical and chemical properties of minerals. This quiz covers the core concepts of mineralogy as a fundamental discipline in earth sciences, including its history and various branches. Test your knowledge on ancient techniques and the evolution of mineral uses throughout time.