Mexican Opal Ring
To learn of Opals click on: https://www.gia.edu/
Mexican Opal Ring
To learn of Opals click on: https://www.gia.edu/
Opal is the product of seasonal rains that drenched dry ground in regions such as Australia’s semi-desert “outback.” The showers soaked deep into ancient underground rock, carrying dissolved silica (a compound of silicon and oxygen) downward.
During dry periods, much of the water evaporated, leaving solid deposits of silica in the cracks and between the layers of underground sedimentary rock. The silica deposits formed opal.
How Opal Forms
Opal is known for its unique display of flashing rainbow colors called play-of-color. There are two broad classes of opal: precious and common. Precious opal displays play-of-color, common opal does not.
Play-of-color occurs in precious opal because it’s made up of sub-microscopic spheres stacked in a grid-like pattern—like layers of Ping-Pong balls in a box. As the lightwaves travel between the spheres, the waves diffract, or bend. As they bend, they break up into the colors of the rainbow, called spectral colors. Play-of-color is the result.
The color you see varies with the sizes of the spheres. Spheres that are approximately 0.1 micron (one ten-millionth of a meter) in diameter produce violet. Spheres about 0.2 microns in size produce red. Sizes in between produce the remaining rainbow colors.
Although experts divide gem opals into many different categories, five of the main types are:
Sapphire is a popular gemstone – and comes in a rainbow of colors. It’s also been long prized, from Ancient Greek rulers to the clergy of the Middle Ages. But where does the September birthstone come from?
A Little Bit about Sapphire
Before we embark on our journey to find the September birthstone, let’s start with a little gemological background.
The September birthstone, sapphire, comes in a range of colors: blue, violet, green, yellow, orange, pink, purple and intermediate hues. The gem belongs to the mineral species corundum: corundum is colorless, but trace elements or color centers (small defects in the atomic structure of a mineral that can absorb light and impart color to the stone) can turn colorless corundum into colorful sapphire. Red corundum is the only color not called sapphire; corundum with this color is ruby.
Where Sapphires Come From: Kashmir
Blue Kashmir sapphire is legendary among gem collectors and jewelry connoisseurs. However, its reputation for gems of unsurpassed beauty rests on stones mined from 1881 to 1887; very little has been produced since then. Sapphire from the mines after this brief window in time varied greatly in quality.
Finding the September birthstone in Kashmir reads like a chapter from an adventure book: we go to northern India, past the picturesque Dal Lake and its famous houseboats, beyond fields of wildflowers and head up into the Himalayas. Our journey takes us on treacherous roads to, as 18th-century explorers described, a “region beyond the snows.” In these remote hillsides, some of the world’s most beautiful sapphires were unearthed.
Fine blue Kashmir sapphire is said to resemble the color of the feathers of a peacock’s neck. Tiny inclusions give gems a velvety appearance. This can look like an extremely fine haze.
A few last facts about Kashmir sapphire: perpetual snow cover makes mining extraordinarily difficult; the mines are exceedingly remote; the weather is severe; and the area is politically contested. Few stones sporadically emerge, and fewer gemologists have researched the mines. That means you’re highly unlikely to find Kashmir sapphire for sale, and if you do, you’ll want a GIA Colored Stone Identification & Origin Report to verify its country of origin. Fine pieces are occasionally sold by leading auction houses.
Where Sapphires Come From: Myanmar
The land north of Mogok, a city in Upper Myanmar. Blue sapphires mined in Mogok tend to have a rich, intense hue; the best of these September birthstones maintain their appearance under all lighting conditions: incandescent, daylight and fluorescent.
The sapphire mines of Mogok share some similarities with the ones from Kashmir: they are remote, hard to reach and are in a politically-charged land. Sapphires from this locale are also rare; they are found near many of the ruby deposits. Mogok is also famed for producing some of the finest pink sapphires in the world.
Where Sapphires Come From: Sri Lanka
Sri Lanka can poetically be called “Treasure Island”. All colors of sapphire, ruby, cat’s-eye chrysoberyl, spinel, garnet, tourmaline, topaz, quartz and many other gems can be found in the Highland Complex, a wide band that runs roughly down the middle of the island. Some of the finest sapphire is also found here, and in riverbeds scattered across the country.
Sri Lanka is perhaps the most famous source for padparadscha sapphires; they are found in river gravel throughout the country. Padparadscha means “lotus flower,” in Sinhalese and this name has been given to the pinkish orange to orange-pink variety of corundum. This sapphire’s color has been likened to the color of salmon, sunset and ripe guava. The cause of color for padparadscha sapphire is due to either trace amounts of iron and chromium or color centers. Fine specimens can sell for as much as a ruby.
Sri Lanka is also a source of the September birthstone in many of its colors: green, yellow, pink, purple, and virtually any color in between. Many in the trade consider Sri Lanka to produce the best range of fancy color sapphires in the world.
Where Sapphires Come From: Thailand
Thailand is an important source of sapphire. Gem fields in Chantaburi, in southeastern Thailand, were mined from the late 1800s to the early 1900s. Sapphire now mostly comes from Kanchanaburi (western Thailand), where it is found in rivers and streams. Most sapphire mined in Thailand is heat-treated to improve its color.
Thailand is one of the world’s major cutting and treatment centers: sapphire from Myanmar, Cambodia, Australia, Madagascar and Sri Lanka are sent here, and end up in jewelry stores in the United States, Japan and Europe.
Where Sapphires Come From: Cambodia
On the western side of Cambodia—in the Pailin Province, near the border with Thailand—sapphire rough lies in riverbeds. Miners sift through the gravel, looking for “Pailin sapphire,” which is understood to be fine-quality blue sapphire that is typically water-worn, rounded and hexagonal in shape. Stones are regularly heat-treated to lighten color and remove or reduce inclusions.
Mining for sapphire in Pailin is extremely demanding. Deadly malaria and a hot climate are working conditions that require muscle and grit. The Khmer Rouge, an oppressive regime that ruled Cambodia from the 1970s to the 1990s, left a legacy of poverty and landmines that still take lives and limbs. Still, in the midst of these most difficult circumstances, miners search for a piece of rough that can change their fortunes.
Where Sapphires Come From: Madagascar
Madagascar, an island off the southeastern coast of Africa, is a rich source of gems: garnet, aquamarine, tsavorite, rubies and of course, the September birthstone. Rough sapphire was found in 1993 in the Andranondambo region of southern Madagascar; and in 1998 in IIakaka – a remote, arid land of plains broken by lonely mountains. A new source was found in January 2016 near Andranondambo in an extremely remote and dangerous location. The mine is accessible only by foot, and the area is rife with bandits.
Many people rank the color of Madagascar’s blue sapphires between Kashmir and Sri Lanka in quality. Rough is often heat-treated to improve color. Slight inclusions are common, as well as color zoning (bands of color).
Madagascar is another source for fancy color sapphire: it produces pinks, blue-violets, yellows, oranges and greens.
Where Sapphires Come From: Other Sources
The September birthstone can also be found in other areas of the world. Australia produces blue, yellow and green sapphires. It is primarily a source of commercial-grade sapphire, and occasionally produces high-quality rough suitable for use in fine jewelry. Commercial-grade sapphire is also found in Montana. Tanzania, Malawi and Kenya – countries in East Africa – are other sources of pink, blue-violet, yellow, orange and green sapphires.
Courtesy of GIA
Peridot is a well-known and ancient gemstone, with jewelry pieces dating all the way back to the Pharaohs in Egypt. The gem variety of the mineral Olivine, it makes a lovely light green to olive-green gemstone. The intensity of color depends on the amount of iron present in a Peridot’s chemical structure; the more iron it contains the deeper green it will be. The most desirable color of Peridot is deep olive-green with a slight yellowish tint. Deeper olive-green tones tend to be more valuable than lighter colored greens and yellowish-greens.
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Ruby is the birthstone for July, and the 15th and 40th year anniversary gemstone.
Undoubtedly one of the rarest gemstones. This aluminum oxide gemstone can certainly protect itself, as it is the second hardest gemstone behind the diamond. The ruby’s extreme durability allow it to be cut into every size and shape, creating unique examples of fine jewelry.
Corundum is the host mineral in which ruby deposits are found; the trace elements introduced into the corundum determine whether or not a ruby is formed. When the coloring agent chromium is introduced, a ruby is produced, while other trace elements will produce the gemstones known as sapphires (iron, for example, is the element responsible for blue sapphire).
Historically the leading ruby-mining countries have been Myanmar (Burma) and Sri Lanka. Today, rubies are found in Thailand, Madagascar, Africa, and Vietnam. Due to the U.S. moratorium on gemstones and pearls from Myanmar, fine rubies are particularly difficult to obtain. Natural rubies are a very slow-growing crystal, making it rare to see a large ruby of almost any quality.
For more info, click on… https://www.gia.edu/ruby
Besides Pearl being June’s traditional birthstone, “Alexandrite” is a lovely alternative.
Those born in June are lucky to claim their birthstone as the beautiful precious gem alexandrite. This exciting gem may appear to be magic when it appears in shades of green and blue or yellow and structure; absorbing light wavelengths within the yellow spectrum, making the gem appear to change color in different light sources.
Alexandrite rose to prominence in 1830 in the Ural Mountains of Russia. Tied to the czar, Alexander II, the gem gets his name from him. The colors of the stone, which change from green to red due to light source, were the Russian flag’s colors at the time. The Ural Mountains were quickly depleted of the gem due to over mining. Russian royals were gifted with alexandrite jewelry in the forms of necklaces and rings.
Alexandrite can be found in Brazil, Sri Lanka, and East Africa.
These changes in color occur in chrysoberyl (alexandrite’s family), wherein aluminum is replaced by chromium ions in alexandrite’s structure; absorbings light wavelengths within the yellow spectrum, making the gem appear to change color in different light sources.
Notable June birthdays include actors Johnny Depp and Chris Evans, musicians Lana Del Rey and Ariana Grande, sports legends Lou Gehrig and Joe Montana, and Hollywood stars including Marilyn Monroe and Tony Curtis, and cutest wargamer Colin Brady 🙂 .
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