A deep blue star sapphire 8 mm x 6 mm cabochon from Thailand. Inclusions of rutile within the stone align with the crystallographic axis of the corundum to produce the star – which is only clearly visible and centered when the back of the stone is cut at 90 degrees to the C-axis of the…

2019 United States Mineral Commodity Consumption Mineral Commodity Million Metric Tons Crushed Stone 1,600 Sand and Gravel 980 Cement 102 Salt 57.0 Gypsum 42.0 Iron Ore 41.0 Phosphate Rock 25.0 Clays 22.0 Lime 18.0 Sulfur 9.4 Potash 5.4 Soda Ash 5.2 Barite 3.0 Copper 1.8 Lead 1.6 Values above are estimates of apparent mineral commodity…

Most rocks are aggregates of minerals. This rock, a granite pegmatite, is a mixture of mineral grains. It contains pink orthoclase, milky quartz, black hornblende and black biotite.

Specimen of rhodochrosite from the Sunnyside Mine, San Juan County, Colorado. Rhodochrosite is a manganese carbonate mineral (MnCO3) that is used as an ore of manganese and is also cut as a gemstone. USGS image.

The mineral “halite” has a chemical composition of NaCl. That means it contains equal numbers of sodium and chloride atoms. In this case they are electrically charged atoms, known as ions. Those ions are arranged in a cubic pattern that repeats in all directions. The small sodium ions are positioned between the larger chloride ions.

Most of the things that we use in our daily life are either made from minerals or produced using mineral products. Antacid tablets are made from calcite, table salt is crushed halite, several minerals are used to make a wood pencil, and dozens of minerals from many different countries are used to make a cell…

Mineral Crystals: The beautiful purple crystals in the photo above are examples of amethyst, a purple color variety of quartz. These amethyst crystals grew in a cavity below the earth and because they grew in an open space they were able to form into six-sided prisms with pointed terminations. The prismatic habit is characteristic of amethyst. Image copyright iStockphoto /…

The primary characteristics of a mineral that determine its physical properties are its composition and the strength of the bonds in its ordered internal structure. Here are some examples: Galena, a lead sulfide, has a much higher specific gravity than bauxite, an aluminum hydroxide. This difference is because of their composition. Lead is much heavier than…

There are approximately 4000 different minerals, and each of those minerals has a unique set of physical properties. These include: color, streak, hardness, luster, diaphaneity, specific gravity, cleavage, fracture, magnetism, solubility, and many more. These physical properties are useful for identifying minerals. However, they are much more important in determining the potential industrial uses of the mineral. Let’s…

The construction industry is the largest consumer of mineral commodities. Crushed stone is used for foundations, road base, concrete, and drainage. Sand and gravel are used in concrete and foundations. Clays are used to make cement, bricks, and tile. Iron ore is used to make reinforcing rods, steel beams, nails, and wire. Gypsum is used to make drywall. Dimension…