What is a Mineral?

A Mineral is a naturally occurring inorganic solid. Unlike rocks, which are a mixture of different materials, a mineral has a highly ordered atomic structure and a definite chemical formula.

• 💎 Crystalline: Atoms are arranged in a repeating 3D pattern.
• 💎 Inorganic: They are formed by geological processes, not living things.
• 💎 Properties: Defined by hardness, luster, color, and streak.

The Mohs Scale

The Mohs Scale of Mineral Hardness is a qualitative ordinal scale. It characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material.

• 1 Talc: Extremely soft, can be scratched by a fingernail.
• 7 Quartz: Hard enough to scratch glass easily.
• 10 Diamond: The hardest known natural mineral.

What is Talc?

Talc is a metamorphic mineral known for its extreme softness and "soapy" feel. It is widely used in cosmetics (talcum powder), ceramics, and paper manufacturing.

• ● Hardness: 1 on the Mohs Scale (Softest).
• ● Luster: Pearly or Greasy appearance.
• ● Chemistry: Mg3 Si4O(10)(OH).

What is Gypsum?

Gypsum is a common saprolite mineral found in sedimentary deposits. It is the primary ingredient in drywall (plasterboard), plaster of Paris, and fertilizer.

• ◈ Hardness: 2 on the Mohs Scale.
• ◈ Varieties: Includes Alabaster and Selenite.
• ◈ Chemistry: CaSO4 cdot 2H2O.

What is Calcite?

Calcite is a primary constituent of sedimentary rocks like limestone and marble. It is highly reactive to acids and is a major component of sea shells and coral reefs.

• ⬗ Hardness: 3 on the Mohs Scale (Scratchable by copper).
• ⬗ Optical Property: Famous for high birefringence (Double Refraction).
• ⬗ Chemistry: CaCO3.

What is Fluorite?

Fluorite is prized by collectors for its perfect cubic crystals and wide range of colors. It is an essential industrial mineral used in smelting and the production of certain glasses and enamels.

• ❖ Hardness: 4 on the Mohs Scale (Easily scratched by a pocket knife).
• ❖ Optical Property: Strong fluorescence under UV light.
• ❖ Crystal System: Isometric (usually forms perfect cubes).

What is Apatite?

Apatite is a group of phosphate minerals. Beyond its beauty as a gemstone, it is the most common source of phosphorus in the world, essential for bio-fertilizers.

• ⬢ Hardness: 5 on the Mohs Scale (Can be scratched by a steel file).
• ⬢ Biological Link: Hydroxylapatite is the main component of tooth enamel.
• ⬢ Crystal System: Hexagonal (Six-sided prisms).

What is Feldspar?

Orthoclase Feldspar is a potassium aluminum silicate. It is the defining mineral for hardness 6, meaning it can scratch glass but can be scratched by quartz.

• ⬓ Hardness: 6 on the Mohs Scale (Harder than a steel needle).
• ⬓ Cleavage: Perfect in two directions at 90circ.
• ⬓ Chemistry: KAl Si3O 8.

What is Quartz?

Quartz is composed of silicon and oxygen (Si O2). It is the second most abundant mineral in Earth's continental crust and is famous for its piezoelectric properties used in watches and electronics.

• ✦ Hardness: 7 on the Mohs Scale (Scratches glass and steel).
• ✦ Fracture: Conchoidal (breaks with smooth, curved surfaces).
• ✦ Varieties: Amethyst, Citrine, Rose Quartz, and Smoky Quartz.

What is Topaz?

Topaz is an orthorhombic mineral. While it is very hard, it possesses perfect cleavage, meaning it can be split by a single sharp blow—a trait that makes it a challenge for gem cutters.

• ✧ Hardness: 8 on the Mohs Scale (Scratches Quartz easily).
• ✧ Luster: Vitreous (Glass-like brilliance).
• ✧ Chemistry: Al2 SiO4(F,OH)2.

What is Corundum?

Corundum is remarkably tough. Because of its extreme hardness, non-gem quality corundum is crushed into "emery" and used as an industrial abrasive for grinding and polishing metals and glass.

• ◈ Hardness: 9 on the Mohs Scale (Only a Diamond can scratch it).
• ◈ Varieties: Ruby (Chromium traces) and Sapphire (Iron/Titanium traces).
• ◈ Density: High specific gravity, making it feel "heavy" for its size.

The Diamond

The name Diamond comes from the Greek adamas, meaning "unbreakable." While it is the ultimate in hardness, it is also highly valued for its dispersion, which splits white light into a rainbow of colors.

• 💎 Hardness: 10 (Highest on the Mohs Scale).
• 💎 Composition: 100% Carbon in a tetrahedral lattice.
• 💎 Conductivity: The best known thermal conductor of all minerals.