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In a previous episode I discussed rocks and minerals and so this episode can be considered a follow up to that one. Gemstones are usually high quality minerals with a crystalline structure. As we'll see, some very common minerals can be considered gems if they're large enough and high enough quality. However, the term gemstone can be a bit of a misnomer as some gemstones are not in fact minerals at all. However, because they're rare and beautiful and look like gems, they they get classified as gemstones in common usage. Gemstones or just gems can be divided into roughly two precious gemstones and semiprecious gemstones. There are only four gemstones that are considered precious diamonds, rubies, emeralds and sapphires. There are at least 200 different types of semi precious gemstones depending on how you define them. I previously did an entire episode on diamonds, so I'm not going to spend too much time on them. Diamonds are pure crystalline carbon that's created under extreme pressures and temperatures down in the earth. The first diamonds were discovered in India, which is considered the historical home of diamonds in the 18th and 19th centuries. However, diamonds were discovered in South Africa and Brazil, greatly increasing the supply. Diamonds are usually clear, but can have other colors based on impurities in the crystal. Rubies are a gem quality version of a mineral known as corundum. Corundum is nothing more than aluminum oxide. Aluminum oxide is extremely common. If you take a piece of aluminum and scratch it, a one molecule layer thick of aluminum oxide will form on its surface. Now you might be thinking that the coating on aluminum doesn't look very much like a ruby, and you would be correct. Rubies are known for their red color, which can vary from deep red to light red, and the word ruby comes from the Latin word for red ruber. What makes a ruby a ruby instead of normal? Corundum are impurities in the crystal from the element chromium. Rubies have traditionally been found in Southeast Asia in the countries of Myanmar and Thailand, with recent discoveries in Madagascar, Kenya and Tanzania. The next precious gem is one that is chemically very similar to ruby sapphire. Sapphires are usually noted by their blue color. Sapphire is also a form of corundum. What differentiates sapphire from ruby is that instead of chromium, a sapphire will have titanium and trace amounts of other elements such as Iron, cobalt, lead, vandium, magnesium, boron and silicon. There is no firm distinction between a ruby and a sapphire. Depending on the color, some pinkish colored gems could be classified as rubies or or sapphires. The word sapphire comes from the Latin word sapphire, which comes from the Greek word for lapis lazui. More on that in a bit. The fourth precious gemstone is emeralds. Emeralds are usually deep green and are a high quality version of the mineral beryl. Beryl is made from beryllium aluminum silicate, and it's usually a light green color. Emeralds are a deeper green that comes from chromium or vandium impurities in the beryl. Like rubies or sapphires, they can range in color depending on the amount of impurities. Some of the first emeralds were mined in ancient Egypt, and there was also production in India and Austria. Today, the most productive emerald mines can be found in Colombia. While today there are four precious gemstones. There used to be five gemstones that were called the cardinal gemstones. The fifth gemstone that used to be considered much more precious than it is today is amethyst. Amethyst is known for its deep, rich purple color. Purple, if you remember back to my episode on the subject, was a very rare color in the ancient world. The dye used to make purple only came from the area around the city of Tyre in Lebanon, and it came from sea snails. Purple became associated with royalty, which along with its rarity, made amethyst valuable. Amethyst is just a form of quartz, an extremely common mineral. Its color comes from impurities, usually iron, and from radiation. Amethyst went from being a precious stone to a semi precious one. Because large quantities were discovered in Brazil. There are additional mines in South Korea, Russia, Uruguay, India and Zambia. And if you've ever seen a geode, a rock filled with purple crystals, those are amethyst. The largest geode ever found is called the Empress of Uruguay, which is 3.27 meters or just under 11ft long. It's estimated to be worth $190,000. And I should add, if quartz has a yellowish hue rather than a purple one, it's known as citrine. As I mentioned before, there are many semi precious stones. Basically, any mineral or stone that looks pretty can be classified as semi precious if there is a market for it. That being said, some semi precious gems are more popular than others. Turquoise is a bluish green mineral that is an opaque hydrated phosphate of copper and aluminum. It is much softer and less durable than other gemstones. It was first discovered in Iran, but large quantities have been discovered in the southwestern United States, particularly in Arizona and New Mexico. Recent deposits have also been found in China. The amount found in the Southwest is why it is so associated with southwestern jewelry and designs. Opals are a unique type of gemstone insofar as they aren't actually minerals. Opals are an amorphous form of silica that usually forms in the presence of water. Opals can take a wide variety of colors and levels of transparency, but they're best known for their ability to flash color. This ability to flash color is known as opalescence. Opals were first mined in Central Europe, but today the best known opal producing region is in Australia. And one of the most productive regions in Australia is the town of Coober Pedy in South Australia. When I was in Coober Pedy, I had the pleasure of going out with an opal miner one day and it was a really interesting experience. Opal mining involves digging random holes and hoping for the best. There aren't opal mines per se like you would have for other gems. You just have a field with hundreds and hundreds of holes. One of my favorite gemstones is peridot. Peridot is a high quality version of the mineral olivine. Olivine isn't created in the Earth's crust, but rather in the earth's mantle. It only comes to the surface via volcanoes. Peridot is olive green due to an iron. In the crystal matrix. There is a magnesium version of olivine which is a more yellowish amber color. If you visit the Big island of Hawaii, walk around on some of the lava fields and pick up some of the pieces of lava rock and and there's a good chance that you may see green flecks in the rock. That stuff is olivine, basically tiny specks of peridot. If you go to the southernmost point of the Big island and go up the east coast about 1 mile, you will find the Greensand beach, which is an entire beach made out of olivine, AKA peridot. Peridot has also been found in meteors, making it one of the only extraterrestrial gemstones. Aquamarine is a very light bluish green version of beryl. It's actually a pretty common mineral and as a result it's pretty cheap. You can find 2 inch aquamarine crystals on Amazon for under $10. Topaz is a silicate mineral of aluminum and fluorine. It's another gemstone that can come in a wide variety of colors, including everything from blue to yellowish orange. Blue topaz is actually quite rare, but it can be created artificially by treating colorless or lightly colored topaz with heat or radiation. As with aquamarine, you can find topaz for pretty cheap. Today, topaz can be found in a variety of global locations, including Brazil, which is now one of the world's largest producers, as well as Nigeria, Pakistan, Madagascar, Namibia, and the United States. Lapis lazoi is not a mineral, but rather a deep blue metamorphic rock that's been prized since early antiquity for its intense color. Although it isn't as prized today, it was highly prized in the ancient world, especially in Egypt. One of the reasons it was so prized is because there isn't a lot of stuff in nature that is a deep blue. In Egypt, it was used in jewelry and ornaments, and it was also ground into powder for use as a pigment called ultramarine in paintings during the Renaissance. The most famous and historically significant source of lapis lazuli is the Sarisong mine in Badakhshan, Afghanistan, which has been in operation for over 6,000 years. Other notable sources include Chile and Russia, although the Afghan lapis lazuli is considered the finest quality due to its vibrant color and minimal calcite inclusions. The last semiprecious gemstone that I'll cover specifically is jade. Jade was considered to be the most valuable gemstone in ancient China. Jade is a term applied to two distinct nephrites and jadeite. Chemically, nephrite is a calcium magnesium silicate, whereas jadeite is a sodium aluminum silicate. Historically, jade has been revered in China, symbolizing purity and moral integrity, and has been used in everything from ceremonial objects to jewelry. The main sources of nephrite jade are found in China, and other significant deposits exist in Taiwan, Russia, and New Zealand. Jadeite is primarily mined in Myanmar, which is known for producing the highest quality jadeite with rich translucent green colors. In addition, Central America, particularly Guatemala, has been a notable source of jadeite dating back to the Mayan civilization. Perhaps the most common interaction people have with gemstones, both precious and non precious, is through birthstones. Depending on which list you use, each month in the calendar is associated with one or more gemstones. The history of birthstones is a blend of mythology, religion, and cultural tradition dating back thousands of years. The concept likely originated from Aaron's breastplate, which was described in the book of exodus and contained 12 gemstones representing the tribes of Israel. Scholars and gem enthusiasts later connected those stones to the 12 signs of the zodiac and later the 12 months of the year. The connection of specific stones to individual months began to take shape in Poland during the 18th century among Jewish gem traders. However, the modern list of birthstones wasn't standardized until 1912 by the national association of Jewelers. In the United States, the list has been updated occasionally to include more abundant or popular gemstones to better suit commercial purposes. Each stone in the list now carries some sort of significance and is thought to bring certain benefits or luck to individuals born in its corresponding month. Weaving together historical beliefs and contemporary consumer culture, this practice has spread globally, making birthstones a popular and meaningful gift choice for birthdays and other significant occasions. The current generally accepted list of birthstones January is garnet, February is amethyst, March is aquamarine, April is diamond, May is emerald, June is pearl, July Ruby, August peridot, September sapphire, October opal, November topaz, and December turquoise. And this might change a little bit depending on which list you look at. The trade of gemstones in ancient times created networks that spanned continents. Routes such as the Silk Road were crucial not only for the exchange of goods, but also for cultural exchanges, including the spread of gemstone usage and lapidary techniques. Gemstones were often gifts between state leaders and played a role in diplomacy and the affirmation of alliances. Today, gemstones are still used as crown jewels as well as inexpensive jewelry. However, the discovery of new deposits and the creation of synthetic versions of many precious stones has dramatically brought down the price. And that means that many gemstones are no longer things for kings and queens, but can be enjoyed by average people as well. The executive producer of Everything Everywhere Daily is Charles Daniel. The associate producers are Austin Otkin and Cameron Kiefer. My big thanks go to everyone who supports the show over on Patreon. Your support helps make this podcast possible, and I also want to remind everyone about the community groups on Facebook and Discord. That's where everything happens that's outside the podcast, and links to those are available in the show Notes. As always, if you leave a review on any major podcast app or in the above community groups, you too can have it read on the show.
