Where Do Gems Come From? Summarizing the Million-Year Process

A rock with gemstones
Photo: Unsplash.com

If you’ve ever had an opportunity to see a gemstone in its raw form, you probably wouldn’t be able to guess how valuable they can be once refined. Gemstones don’t form just like that; it takes thousands to millions of years. It’s their rarity and the tough process of extraction that makes them such a valuable commodity!

While most people are fond of gemstone jewelry, gem collectors are more interested in knowing where they come from. If you’re among the latter, you may be interested to know how the breathtakingly-beautiful ruby gets formed or how the sparkling sapphire came into existence. If so, you’ve come to the right place. This blog post summarizes the million-year process of gem formation. Let’s hop into the topic without any further delay.

The Origin of Gemstones 

Simply put, gemstones come from rocks. Rocks are made from an assortment of different minerals. The most common minerals that are most abundant in rocks include silicates like mica, olivine, quartz, emeralds, oxides, carbonates, halides and sulfides. Many minerals come together to form beautiful and unique crystals and out of these crystals, gemstones are the most valuable. Gems look quite ordinary in their raw, uncut form, but once they are extracted, cut and polished, the luster and brilliance are just incomparable!  

How Are Gemstones Formed?

Most gemstones are formed inside the earth’s crust, which is the top-most layer. They’re usually created at a depth of 3-25 miles. However, some gemstones from deeper down in the mantle. These include peridot and diamonds. The mantle mostly consists of magma, which is molten rock.

Since most of the gemstones form in the earth’s crust, let’s look at the crust a bit in detail. The crust comprises three different kinds of rocks; igneous rocks, metamorphic rocks and sedimentary rocks. They differ in the way they’re formed. Some gemstone varieties may be formed from any one type of rock, while others may be associated with multiple rock types. 

Igneous Gemstones

The igneous rocks are formed by the solidification of magma that rises to the crust from the mantle through volcanic pipes. Once it reaches the surface, it’s exposed to a contrastingly lower temperature, and as a result, it solidifies. However, if the process of solidification is slow and gradual, it can crystallize to form minerals. Some of the gemstones that are formed through the igneous process include quartz (ametrine, amethyst, etc.), garnet, apatite, moonstone, aquamarine, topaz, tourmaline and zircon.

Sedimentary Gemstones

After the igneous rocks reach the earth’s surface, they’re exposed to weathering and erosion, causing them to deteriorate into smaller particles. These smaller particles are moved by water and wind and with time, the layers of these smaller sediments build up underwater or on land. As the sedimentation continues, the pressure by the upper layers results in the layers below to become compressed and compact. They also undergo numerous physical and chemical changes that eventually lead to the formation of sedimentary rocks. Gem formation that occurs through sedimentation results in the formation of sedimentary gemstones that include opal, jasper and malachite.

Metamorphic Gemstones

Some processes put the minerals of igneous rocks and sedimentary rocks under immense pressure and heat that brings about a change in their structure and chemistry. These processes include contact metamorphism and regional metamorphism. As a result of excessive heat and pressure, igneous and sedimentary rocks are converted into metamorphic rock. The gemstones that are formed as a result of metamorphosis include turquoise, ruby, jade, zircon, sapphire, etc.

The rocks are constantly changing. And all of this doesn’t occur overnight. It takes millions of years. It took your favorite ruby that you so fondly wear around your neck at least several thousands of years to be what it is today.

What Makes Gemstones So Precious?

Gemstones aren’t waiting on the earth’s surface where you can pick them up like you pluck a flower or a seashell. They’re embedded in rocks, such that you can’t even tell if a particular piece of rock has gems in it. They are difficult to locate and extract. As the saying goes – best things don’t come easy and that sits fit in the case of gemstones! 

Even after gemstones are extracted from the rocks, it takes a lot of effort to bring them into a shape that is lustrous and attractive. You wouldn’t want to wear a pendant with an unrefined piece of rock around your neck, would you? It’s the shine, color and luster that make gemstones so highly attractive. 

Gem formation takes millions of years. Assuming that all the gemstones present today are extracted from the earth, we won’t have any new supply of gems for the next thousands of years. The million-year process of gemstone formation is one of the reasons why gemstones are so precious. 

All minerals are precious, some more than others. The value of gems depends on how common or rare they are. The more widely a gemstone is available, the less expensive it’ll be. They’re divided into different categories; precious, semi-precious and organic. Precious gemstones include ruby, sapphire, diamond, and emerald. Semi-precious gemstones include opal, topaz, jade, and others. Organic ones include pearl, coral, and amber. 

Closing Word 

Now you know where gems come from – they come from rocks! The type and quality of a mineral depend on the type of rock it comes from. While all gems are precious, the varying mineral composition gives them a characteristic color and appearance.

Gemstones are widely used in jewelry. A lot of people are involved in gem trading. And many people simply love to collect them. Knowing that a gemstone goes through multiple stresses over tens and thousands of years before taking the form we see today, there is no doubt that people consider them as highly precious assets! 

How Planets and Stars Compare

 
Photo of the Sun by NASA
Photo by NASA on Unsplash

Why is it that you can’t look at the sun for more than 1/2 second? What would happen to you? No doubt you will need a trip to the optometrist or worse, you may go blind!

So, what is it that causes this object that is 93 million miles from Earth so powerful? Simply speaking, the sun is a star, and just like any star, they are extremely large in comparison to planets and carry the equivalent of millions of atomic bombs that ‘explode’ every second.

Learning how planet sizes compare to each other, then how the different stars compare to each other is a worthwhile journey and one that fascinates many. Once you read this article, you may find it inconceivable to try to comprehend the size of our universe. In one word – Mind-boggling.

Comparing Our Planets to Each Other

Photo by Ross Sneddon on Unsplash

Planets are a mere spec in our galaxy.  In the first illustration below, we compare the eight planets in our solar system. From the left, we have Saturn and Jupiter. Middle, we have Uranus and Neptune. The front row is Mercury, Venus, Mars, and Earth. Note how Jupiter can engulf Earth by about 50 times.

In our next image, we move closer inward and look at the inner solar system. There is an error in the image below. Can you find it?

Pluto does not belong here for two reasons. (1) It is not part of the inner solar system and (2) it is not considered a planet anymore.

Comparing the Sun to the Planets

This image shows the planets compared to our sun. The Earth here is now hardly visible. Even Jupiter is the size of a pea compared to the sun. If the sun was a basketball, then Jupiter would be a pea.

Think the sun is big! Think again. The image below compares the sun to the star giant Arcturus, which is 37.5 light-years from Earth and is larger than the entire orbit of Mercury. Read more about Arcturus here. Another basketball to pea scenario.

Comparing Other Stars to Each Other

If these sizes don’t fascinate you, take a look at the next illustration, showing Arcturus paired with the star giants Betelgeuse and Antares. Forget about trying to see any of our planets here, as the sun is a mere pixel on the screen. That would equate to a grain of sand against a basketball (Antares). See our summary below.

We hope these comparisons give you a better appreciation and respect for the galaxy and the universe.

Summary:

We started with a comparison of Earth to the four inner planets in the solar system. Earth appears the largest. Then Earth and the inner four planets are compared to the outer planets and Earth now appears like a pea to a basketball (Jupiter).

Next, all the planets in our solar system are compared to our Sun, a medium-sized star in the Milky Way galaxy. Continuing to use the pea as our example as Earth and the basketball as Jupiter, the sun would be the size of a 10-story building. Putting a pea and a basketball next to this building, well you can start to appreciate the immense sizes of the objects in space, but we haven’t even scratched the surface yet.

The image below is an estimated comparison between planet Mars’s orbit superimposed on the giant star Antares. Notice how Antares engulfs its orbit with room to spare. Earth would not be visible here, nor would Jupiter.

One could only imagine the immense gravitational pull this star would have on any objects coming close to it. Future black hole?

Well, we don’t stop here. The largest known star is UY Scuti, located in the constellation Scutum, it is 1700 times larger than the Sun.

With stars this big, one can only imagine the great gravitational pull they will have on other objects in their neighborhood, and in so doing, we can begin to understand how black holes can be formed.

View this video of planetary and star comparisons, as well as the video creator’s view of intelligent life in the universe.

There is also a fascinating website called Scale of the Universe which will help you look at the ‘big picture’, pun intended.

March 2015 – R131 in the Large Magellanic Cloud was recently found to be the largest star to date.

Planet Earth is a Lot More than You Could Imagine

View of the Earth

How old do you think the Earth is? Never mind, we’ll tell you. It’s almost 4.54 billion years old!

Let that sink in. The planet may be old but it has all the ingredients to make your jaws drop and eyes pop! How else would you describe the mighty volcanoes and the drifting plates, the oceanic abysses and the meteor crashes?

Even with geologists and scientists constantly being on the hunt for new discoveries, there is so much about the planet that is yet to be discovered. In this post, we are going to give you the smallest gems from the treasure trove that is our planet.

And the Rocks Walk

Don’t believe us? Take a trip down to the Death Valley. There at the Racetrack Playa (a pancake-flat lakebed) and the rocks walk. In times when there are storms, there are instances where rocks weighing tens and hundreds of pounds can move down a distance. When there’s no storm, there’s a nice wind that gives the rocks the kick start they need.

Where’s the Longest Chain of Mountains

Mountains in Colorado Springs
Mountains in Central Colorado

If you’re thinking it’s the Andes, you’re wrong. To locate the largest range of mountains on the planet, you’d have to take a swim into the ocean. The Mid-Ocean Range stretches across a distance of 65,000 km on the seabed. Compare the Andes’ 7,000 km stretch to that!

This chain of volcanic mountains maintains an average height of 18,000 feet above the sea bed. But here’s the most fascinating fact: This mountain range is not stopping! As volcanoes erupt, they create sufficient crust to add more underwater mountains to the already global mountain range.

Ever Heard of the Exploding Lakes?

They do exist! The kivu, Nyos and Monoun Lakes in Cameroon and on the Congo-Rwanda border actually explode. These deadly crater lakes are situated above volcanic Earth. The magma beneath the releases gusts of carbon dioxide into the lake water. This creates a deep layer rich in carbon dioxide right above the lake beds. This carbon dioxide at times explodes, and is fatal enough to suffocate a passerby to death.  

Lake Nyos (Wikipedia)

Where Giants Breathe

No we’re not talking about the Yetis or the Bigfoot! The next things that come to mind when we think about giant life are elephants and whales. But could you think of a tree being larger than these creatures? The General Sherman is a giant sequoia that stands at 311 feet tall (A blue whale roughly grows to a 105 feet long) with the largest known stem volume on Earth. The General Sherman’s trunk measures a tad bit more than 52,500 cubic feet. That is colossal!

Did you know that there are actually spots on Earth where no precipitation has been recorded – EVER!

The center of the Atacama Desert in Peru and Chile has seen no rain whatsoever. It is known as the driest place on the planet. That’s not all. The orb we inhabit is constantly evolving, there’s always a new surprise about the Earth popping up every now and then. Take the time to imagine the extent of things we’re yet to discover about the fascinating planet we live in!

The Science Behind the Age of the Earth

View of the Earth

How do you calculate your age? You simply subtract your birth year and current year. But when it comes to determining the age of the sprawling sphere which we call home, Earth, it becomes a bit trickier. Let’s explore what science has to say about the age of the Earth.

The age of the Earth couldn’t be guessed by anyone before the process of radiometric dating came into play. In 1898, the pioneer of radiology, Marie Curie discovered the phenomenon of radioactivity. The atoms either decay or lose energy by emitting radiation in the form of electromagnetic waves or particles. Later, in the year 1904, Ernest Rutherford, the famous physicist determined how this decay could let them explore the age of old rocks.

radiometric dating illustration
licensed under the Creative Commons
© Eugene Alvin Villar, 2008

With this exploration, Arthur Homes, who was completing his geology degree in London, acted as a helping hand by developing a new technique of dating rocks using the uranium-lead method. He applied this technique to the oldest rock and got to know its age. Applying a similar technique to calculate the age of the Earth made him reach the conclusion that the Earth was at least 1.6 billion years old.

But wait, this is not the actual age of the Earth! Earth’s age has always been hotly debated among scientists over the years. That is why several revisions have been made. Later, in the 1920s, an unknown scientist declared that Earth’s age was approximately 3 billion years. This suggested that the Earth was even older than the universe, which itself was thought to be 1.8 billion years old.

Later, the scientists declared that radiometric dating of the fragments from the Canyon Diablo iron meteorite was the best estimate for calculating the age of the Earth. From those fragments, they got to know that the true age of Earth was 4.56 billion years.

Since then, scientists have been using radiometric dating to determine the age of extraterrestrial objects such as Earth, meteorites, space rocks and moon rocks. For many years, scientists have tried to determine the exact age and now that they have discovered its age using the radiometric dating, they are using it for several other space objects as well.

     

Building a Great Mineral Collection: How to Care for Gemstones

Close-Up Photo Of Assorted Gemstones

You purchase a beautiful emerald for your mineral collection but forgot to maintain it properly. One year later, you find it in your drawer with much of its luster lost. Why? In our recent blog, we discussed guidelines for investing in gemstones. Now, let’s take a look at how to care for your investment. You need to be aware of the dos and don’ts regarding the maintenance of gems. One wrong move and they can lose their shine (and value) for life.  

Gem Maintenance Overview

In addition to a mineral’s rarity and alluring beauty, they are prized for their durability. In fact, their natural toughness is one of the main reasons why gemstone collections have become such a popular mode of investment today. However, you would be wrong to think that given their literal rock-strong build, these ornate stones don’t require any maintenance. 

Whether you plan to sell them down the line or not, it’s essential to know how to care for them. Improper storage and negligence in cleaning these minerals regularly or with the wrong substance are rookie mistakes many gem collectors make. This can have an adverse effect on the beauty and brilliance of these stones. This, in turn, can greatly reduce their total worth and hence, any potential profits you can make by selling them.

Here are some important tips on how to look after your gemstones and maintain their exquisite beauty.

Cleaning Your Gems

A 2 carat diamond being held up by tweezers

It doesn’t matter whether they are tucked away safely in a box or displayed openly on your shelf. Gemstones need to be cleaned periodically. Cleaning is quite easy and should only take a couple of minutes. 

Generally, all you need to do is rinse them with lukewarm water. This washes off the dirt and dust that may have settled on the surface. In some cases, you might need to add a bit of soap or other mild detergent to remove hard stains. 

If you have just mined a piece from a public gemstone dig site, you will need to clean it more thoroughly to get rid of all the soil and grime. 

Depending on the size and texture of the stone, a small cleaning brush with soft or medium-hard bristles would suffice. Most of the time, a toothbrush or paintbrush works well, so grab one and gently scrub.

Clean it in a slow, circular motion. Avoid scrubbing too harshly as it can scratch the stone. 

For very small-sized gems that are hard to clean with a brush, dip them in a bowl of soapy water. Then rub each piece gently between the tips of your fingers to remove the dirt stuck to it.

Once clean, immediately dry the stones using a soft, lint-free cloth. 

Pro tip: Never wash your gemstones directly in the sink as you risk losing them easily.

Cleaning Specific Gemstones

The Diamond
“Diamond” by nikilok is licensed under CC BY 2.0

The above method of cleaning is generally safe for most rock minerals and crystals such as emerald, jade, granite, amethyst, corundum and others that are similar in chemical composition. 

However, you should try to research about the nature of each gem in your collection. This is because some of these tend to be of quite a sensitive nature. Cleaning your minerals too frequently or with water that isn’t at the right temperature can dull their luster permanently.

For example, turquoise and amber have a relatively lower resistance than most gemstones. Using detergents or warm water to clean them can result in a change in color due to chemical reactions. 

Here are some important considerations for some of the common minerals that require extra care to handle:

  • Peridot – Peridot is quite soft compared to an average gemstone. Avoid putting too much stress otherwise it may crack.
  • Turquoise – Store it in an airtight box or plastic bag as moisture from the air can stain its surface over time
  • Garnet – Garnet is heat sensitive so avoid prolonged exposure to warm water
  • Pearls – Wash them with plain lukewarm water. Dipping them into chemical solutions can discolor the outer layer
  • Aquamarine – Keep in a soft pure cotton cloth after cleaning as aquamarine is prone to scratches. 
  • Opal – Do not wash it with warm water as it is extremely sensitive to heat. Wrap in a soft fabric before storing it. 
  • Sapphire – Keep it away from stones like diamond and ruby as their hard edges can scrape its soft surface 
  • Diamonds – Being the hardest of all gemstones, they bear heat and pressure well. Mechanical cleaning is often the go-to method for restoring their shine. However, always hand clean it properly first to avoid scratching during the mechanical cleaning process.

Using an Ultrasonic Cleaner

Some expert level gem collectors like to use special equipment such as ultrasonic cleaners. These home kits are basically made for cleaning crystal and stone-embedded jewelry. Most of them have a steam and boiling system to take your gems from dull to dazzling in no time.

It is quite an efficient and effective way to maintain a large assortment of gemstones in prime condition. But it is usually not recommended for beginners.

The heat and concentrated chemical solutions used in these cleaners can damage your stones if there is a slight oversight on your part. Plus, it is not suitable for all types of stones. If you want to use such advanced methods to restore the shine, it’s better to leave it to the professionals. 

Take your collection to a jeweler and they can clean it for you.

How to Store Gemstones

Opal sterling silver bracelet
Opal sterling silver bracelet hand made in Belize

When it comes to storing your gemstones, just remember this one cardinal rule: keep them away from heat and sunlight at all costs. 

Heat and light, especially ultraviolet rays in sunlight can have an adverse effect on the color and durability of these minerals.

Stones like amethyst and quartz can become dull and tarnished if kept under direct sunlight. Storing your gems in a high temperature environment can also dry up their natural moisture. 

Microscopic water droplets play an integral role in holding the structure of mineral rocks together. Reduced water content can cause a fracture in these stones. 

Also, remember to always wash your hands thoroughly before touching any gemstones. Chemicals from hand moisturizers, perfumes or even the natural salts and other compounds in our sweat can be damaging for their natural glitz. 

End Note

Building a gemstone collection is fun and exciting. But you must remember that although mineral rocks have high resistance, they are not indestructible altogether. To maintain their beauty, you need to store them properly and clean them periodically.

Follow these tips on how to care for gemstones and rest assured they will retain their shine and luster for years to come.