Mineral Mayhem
Minerals - the things you never think about but are, in fact, everywhere.
Mineral Basics
What is a mineral?
Since we're going to be discussing the importance of minerals to our everyday lives, we should start at the beginning with the important question - what exactly IS a mineral? Well, as it turns out, it depends on who you ask.
- Geologist: a mineral is a naurally occurring, inorganic, solid element or compound that has a definite chemical composition and an orderly internal structure. Minerals are identified by their characteristic physical properties.
- Doctor or Nutritionist: a mineral is an inorganic substance that organisms (humans included) need to grow, repair tissue, metabolize, and carry out other essential bodily functions.
- Swedish Botanist Carolus Linnaeus (1707-1778):
"Natural bodies are divided into three kingdoms of nature: viz. the mineral, vegetable, and animal kingdoms. Minerals grow, Plants grow and live, Animals grow, live, and have feeling."
I think we can summarize minerals with the following: they are solid, natural (man-made minerals don't count), they have definite chemical compositions and structures, and each specimen of the same mineral will have the same physical characteristics. Some minerals are even essential to life. While minerals do grow (atoms and elements join to form molecules), I think if Linnaeus was alive today he'd probably agree with our current definitions, given the advancements we've made in science since the 1700s.
How many minerals exist?
Again, it depends on who you ask. The general consensus is that there are between 4,000 and 5,000 naturally-occurring minerals but out of those thousands of minerals, there are only a handful that are known as "rock-forming minerals". The rock-forming minerals, which make up nearly 90% of the rocks in Earth's crust, are feldspars, quartz, amphiboles, micas, olivine, garnet, calcite, and pyroxenes.
Rock-Forming Minerals
Feldspar refers to a large group of minerals that make up nearly 50% of Earth's crust. Feldspars are silicate minerals, which means they're composed of silicon and oxygen, with accessory minerals such as calcium, potassium and aluminum.
Two common varieties of feldspar are plagioclase feldspar and alkali feldspar.
Feldspars can be creamy to pinkish in color and are used most commonly to make glass and ceramics.
Quartz (SiO 2 ) makes up about 12% of Earth's crust and is the second most abundant mineral after feldspar.
Pure quartz is clear, but impurities can cause color changes to a nearly every color imaginable. Some of the most common colors of quartz are purple (amethyst), white (milky), black (smoky), pink (rose), and yellow/orange (citrine).
Quartz is used in circuits for electronic products like cell phones and TVs, in glassmaking, oscillators in watches and clocks, and as an abrasive for sandpaper.
Amphibole refers to a group of minerals that are found predominantly in metamorphic and igneous rocks. One of the most common members of this mineral group is hornblende, pictured here.
Amphibolite is dark colored, heavy and can be easily polished. Since they have a nice shine when polished, amphibolite minerals are used as building stones (building facings and veneers). These minerals are also used as crushed stone, but due to its weight, it's usually used in areas where it's quarried to reduce transportation costs.
Micas are a group of minerals that make up about 4% of Earth's crust. They're silicate minerals and can be flaky or occur in sheets, both of which are thin and flexible.
There are 37 different mica minerals, but two of the more common ones are black biotite mica and clear muscovite mica.
Mica is used in gypsum wallboard joint compound as a filler, as a pigment in paint, and as a reinforcement agent in the plastics industry. Mica is heat resistant and doesn't conduct electricity.
Olivine is the dominant mineral in Earth's upper mantle. It's composed of magnesium, iron, and silicon dioxide and is typically found in igneous rocks such as basalt, gabbro, diabase and peridotite.
Translucent olivine is often called peridot, and is used as a gemstone. Olivine doesn't have many industrial uses but can be used in metallurgical processes and in blast furnaces to remove impurities from steel.
Garnet is a silicate mineral group, which means it has SiO 4 as part of its chemical composition. Garnet minerals are found in all three types of rocks and most are formed when sedimentary rocks are metamorphosed with high heat and pressure.
Although most garnet is red, it can be almost any color except blue.
Garnet is mostly thought of as a gemstone, but it has lots of industrial uses like abrasives, water filtration, and abrasive powders.
Calcite belongs to a group of minerals called carbonates. It's chemical formula is CaCO 3 . Calcite is the principle component of the sedimentary rock limestone and its metamorphic twin, marble.
Calcite is broken down and reacts in the presence of acid. Since limestone is primarily composed of calcite, limestone will also break down in the presence of acid, like acidic rainfall. This is why sinkholes form in areas that are underlain by limestone.
Calcite is used as aggregate in construction and is used as a component of lime and cement. It's also a great acid-neutralizer for the chemical industry - neutralizing acid mine drainage, neutralizing acidic farm fields, and even reducing acid in our stomachs (antacids).
Pyroxene is a group of minerals known as ferromagnesian silicates. This means they are silicate minerals that have iron, magnesium, and calcium varieties. They are a very common rock-forming mineral group and make up approximately 10% of Earth's crust.
One of the common pyroxene minerals is called spodumene (shown here), which has lithium as a component of its chemical composition. Valuable deposits of lithium are found here in North Carolina and as you probably know, lithium is a necessary component of lithium-ion batteries.
Minerals, minerals everywhere
Minerals are, quite literally, everywhere. They play an essential role in your life, from the time you wake up until the time you go to bed, yet most of us never give minerals a second thought. Heck, we don't even give them a first thought! According to the Minerals Education Coalition , every American born will require 3.02 million pounds of minerals, metals, and fuels in their lifetime. Check out their website for more information. Now, let's break it down to find out why minerals (and the geologists who find and mine them) are critical.
Home Sweet Home
The graphic here shows just a fraction of the minerals that were used to construct your home as well as the products inside. You likely wake up with minerals (clock), ingest minerals (toothpaste), and eat on plates made from minerals, all before 10am.
Just a few of the minerals in your home
Let's hit the road
Grab your coffee and get ready to hit the road to work, school, or wherever your day takes you. Think you've escaped the mineral mayhem for this part of your day? Think again...they're everywhere! Be sure to click right in the section below to view automobiles, roads, and cell phones.
Fill 'er up!
Your work/school day is done but before heading home, you should make a stop to refuel. Not that kind of fuel, though. We're talking about the type of fuel you can get at the grocery store that contains essential minerals for your body's health and functions. See below for a few examples.
Calcium
Calcium - tofu, dairy, sardines. Source: Flickr
Copper
Copper - oysters, shitake mushrooms, cashews. Source: Flickr
Iron
Iron - spinach, chickpeas, red meat. Source: Flickr
Magnesium
Magnesium - avocado, dark chocolate pumpkin seeds. Source: Flickr
Other minerals essential for our bodies to grow, repair, and metabolize are manganese (garlic, cashews), phosphorus (pumpkin seeds, eggs), potassium (radishes, coriander), sodium (olives, salt), selenium (pork, beef, chicken), sulfur (turkey, legumes, garlic), and chloride (seaweed, tomatoes, celery).
Critical Minerals- what and why
The U.S. Energy Act of 2020 defines a "critical mineral" as a non-fuel mineral or mineral material essential to the economic and/or national security of the U.S. and which has a supply chain vulnerable to disruption. Critical minerals can change over time as supplies and society's needs fluctuate. The minerals currently on the list are deemed critical to our society's high tech needs such as: high-tech devices like smartphones and computers, clean energy infrastructure (EV cars, wind turbines, solar panels), semi-conductors as well as for defense, aerospace and medical applications.
The U.S. does not produce all of the 50 critical minerals on the list and is therefore reliant on other countries to supply them. There are risks to relying on other countries for critical minerals - social unrest, market fluctuations, natural disasters, war, and pandemics can cause supply chain disruptions. The U.S. Energy Act of 2020 addresses the availability, development, and production of critical minerals by providing incentives to increase domestic production of critical minerals that are needed to ensure the economic and national security of the United States.
List of Current Critical Minerals
Where in the world?
Where do all the minerals come from? This is a hard question to answer because minerals deposits are found all over the world. A mineral deposit is a natural concentration of minerals in the Earths crust. Whether or not the mineral gets extracted from Earth's crust is dependent on several factors including, but not limited to: the concentration of the mineral deposit, the demand for the mineral, the cost of removing the deposit (including the overlying rocks), and the cost at which that mineral can be sold on the market.
The USGS created a magnificent interactive map of major mineral deposits all over the world. You can click on any of the points on the map to learn about the minerals that are found there. Check it out below!
Mineral Deposits of the World
What about gems? Are they minerals?
Source: Wikimedia Commons
Most of the time, yes, gems are specimens of minerals. However, there are a few gems like lapis lazuli that are rocks. In order to qualify to be a gem or gemstone, the mineral (or rock) has formed crystals that are professionally cut, polished, and/or engraved and made into a prized piece, such as jewelry. Semiprecious gems include amethyst, garnet, citrine, turquoise, and opal. Precious gems include diamond, emerald, ruby, and sapphire. Did you know that emerald is the State Mineral of North Carolina?
Speaking of North Carolina...
North Carolina is definitely part of the mineral mayhem, as we produce and export many minerals, including some of those deemed to be critical. The mineral resources page of our website is going through a growth spurt, so please check back in a few months when we've had time to grow into our new look, which will include minerals information in interactive formats. In the meantime, here are some tables outlining North Carolina minerals.
Minerals of North Carolina
Thanks for joining the NC Geological Survey on this trip into mineral mayhem. If you have any questions or comments, please reach out to Education and Outreach Coordinator Amy Pitts .
