Description

Tanzanite is a captivating gemstone known for its striking color and rarity. It is a variety of the mineral zoisite and exhibits a unique blue-violet hue, making it highly sought after in the gemstone market. Tanzanite is found exclusively in a small area near Mount Kilimanjaro in Tanzania, which contributes to its exclusivity and allure. This gemstone has gained immense popularity and significance since its discovery, becoming a symbol of elegance and luxury.

Tanzanite is a member of the epidote mineral group and is scientifically classified as a variety of zoisite. It is renowned for its vivid colors, ranging from deep blue to vibrant violet, often displaying a mesmerizing play of colors due to its trichroic nature. This means that tanzanite can show different colors when viewed from different angles, including blue, violet, and burgundy. The gemstone is prized for its exceptional brilliance and clarity, making it a popular choice for fine jewelry.

Discovery and Significance in the Gemstone Market

Tanzanite was discovered relatively recently in 1967 by a Maasai tribesman named Ali Juuyawatu in the Mererani Hills near Arusha, Tanzania. The gemstone was initially mistaken for sapphire due to its intense blue color. However, after further analysis, it was identified as a new variety of zoisite. Tiffany & Co., a renowned American jewelry company, recognized its potential and introduced it to the global market under the name “tanzanite,” highlighting its unique origin. Since then, tanzanite has become one of the most popular gemstones, particularly in the United States and Europe, with its popularity rivaling traditional gems like sapphire and emerald.

Product Information

Gemstone Name	Natural Tanzanite Earrings
Dimension	23.47 x 8.77 x 24.28 mm
Material	Silver
Birthstone	December
Weight	5.95 carats

Importance of Tanzanite

Tanzanite’s allure lies in its remarkable color, rarity, and optical properties. Its trichroism, combined with a vivid blue-violet hue, makes it distinct from other gemstones. The depth and richness of its color are unparalleled, often described as a blend of sapphire blue and amethyst purple. Additionally, tanzanite is relatively soft compared to other gemstones, with a Mohs hardness of 6 to 7, requiring careful handling and setting in jewelry. Despite this, its unique color and brilliance continue to captivate gem enthusiasts and collectors worldwide.

Tanzanite plays a crucial role in the economy of Tanzania, as it is the sole source of this gemstone globally. The mining and export of tanzanite contribute significantly to the country’s GDP and provide employment opportunities for thousands of Tanzanians. The government of Tanzania has taken steps to regulate the tanzanite industry to ensure sustainable mining practices and maximize revenue from this precious resource. Additionally, tanzanite has become a symbol of national pride and cultural heritage for the Tanzanian people, attracting tourists and gem enthusiasts to the region.

In conclusion, tanzanite’s unique properties, captivating beauty, and limited availability make it a gemstone of great significance in the global market. Its discovery has not only enriched the world of gemstones but also played a vital role in the economic development of Tanzania. As demand for tanzanite continues to grow, its status as a symbol of elegance and luxury is further solidified, ensuring its place as one of the most treasured gemstones in the world.

Geological Aspects of Tanzanite

Tanzanite is a gemstone that stands out due to its geological formation, composition, and rarity. Its discovery and mining are concentrated in a specific region, adding to its exclusivity and allure in the gemstone market. Here is an in-depth look at the geological aspects of tanzanite:

Formation and Composition

Tanzanite is formed under unique geological conditions that occur only in a small area of northern Tanzania. This region is part of the East African Rift, a tectonically active area that provides the necessary conditions for tanzanite formation. Tanzanite is created when the mineral zoisite is exposed to high temperatures and pressure over millions of years.

The formation process involves the metamorphism of calcium-rich rocks in the presence of vanadium, which gives tanzanite its distinctive blue-violet color. The combination of tectonic activity, specific mineral content, and geological conditions makes tanzanite formation an exceedingly rare occurrence.

Chemical Composition and Physical Properties

Tanzanite is a variety of the mineral zoisite and is chemically classified as a calcium aluminum silicate hydroxide with the formula (Ca(_2)Al(_3)(SiO(_4))(_3)(OH)). Its vibrant color is primarily due to the presence of trace amounts of vanadium within its crystal structure.

Tanzanite has several notable physical properties:

• Trichroism: Tanzanite exhibits trichroism, displaying different colors—blue, violet, and burgundy—when viewed from different angles.
• Hardness: It has a Mohs hardness rating of 6 to 7, making it softer than many other gemstones and requiring careful handling in jewelry settings.
• Cleavage: Tanzanite has perfect cleavage in one direction, meaning it can be easily split along specific planes, which poses challenges in cutting and setting.
• Luster: It possesses a vitreous luster, contributing to its brilliant appearance when polished.

Tanzanite Mining Regions

Tanzanite is found exclusively in a small region near Mount Kilimanjaro in northern Tanzania, within the Merelani Hills. This area is the only known source of tanzanite in the world, which contributes significantly to its rarity and value.

The mining area is divided into four blocks (A, B, C, and D), each allocated to different mining operations. The largest and most productive of these is Block C, which is mined by large-scale operations, while smaller blocks are mined by artisanal miners.

Methods of Extraction and Challenges Faced in Mining

The extraction of tanzanite involves both large-scale mining operations and small-scale artisanal mining. The methods of extraction include:

• Open-pit mining: This method is used in areas where tanzanite is located near the surface. It involves removing layers of soil and rock to access the gemstone-bearing deposits.
• Underground mining: For deeper deposits, underground mining is employed. This involves tunneling into the earth to reach the tanzanite-bearing veins.

Challenges faced in tanzanite mining include:

• Safety hazards: Mining conditions can be dangerous, with risks of cave-ins and accidents due to the unstable nature of underground tunnels.
• Regulation and legality: Artisanal mining often occurs with limited regulation, leading to illegal mining activities and smuggling.
• Environmental impact: Mining can lead to land degradation and environmental concerns, prompting the need for sustainable mining practices.

Rarity and Exclusivity

Factors Contributing to Tanzanite’s Rarity

Several factors contribute to the rarity of tanzanite:

• Geological exclusivity: Tanzanite is only found in a small region of Tanzania, making it geologically rare compared to other gemstones found in multiple locations.
• Limited supply: The finite nature of tanzanite deposits means that its availability is limited, with estimates suggesting that the current supply may be depleted within a few decades.
• Unique conditions: The specific geological conditions required for tanzanite formation occur in a limited geographic area, further contributing to its rarity.

Comparison with Other Gemstones

Tanzanite is often compared to other blue gemstones like sapphire, but its unique color and properties set it apart. While sapphire is more durable with a higher Mohs hardness of 9, tanzanite’s distinctive trichroic color and rarity make it equally desirable.

In terms of exclusivity, tanzanite is more geographically restricted than most other gemstones, such as diamonds, rubies, and emeralds, which are found in various parts of the world. This exclusivity enhances its allure and makes it a sought-after gem for collectors and jewelry enthusiasts.

In conclusion, tanzanite’s geological formation, unique composition, and limited geographic availability make it a gemstone of exceptional rarity and exclusivity. Its captivating beauty and rich color, combined with its rarity, continue to fuel its demand and value in the global gemstone market.

Physical properties

1. Color: Tanzanite is renowned for its captivating blue-violet color. The gemstone exhibits a range of shades, from a vibrant blue to a deep violet. The intensity of the color is a crucial factor in determining the value and desirability of Tanzanite.
2. Clarity: Tanzanite can vary in terms of clarity. It may contain inclusions, which are natural internal flaws or tiny mineral crystals within the gemstone. The presence of inclusions can affect the transparency and overall appearance of the stone. Tanzanite with high clarity and minimal inclusions is considered more valuable.
3. Hardness: Tanzanite has a hardness of 6.5 to 7 on the Mohs scale of mineral hardness. This makes it relatively durable and suitable for jewelry use. However, it is important to note that Tanzanite is not as hard as gemstones like sapphires or diamonds, so it requires careful handling and protection to avoid scratches or damage.
4. Crystal Structure: Tanzanite belongs to the orthorhombic crystal system. Its crystals have a prismatic shape with well-defined facets. The crystal structure of Tanzanite contributes to its pleochroism, where the gemstone displays different colors when viewed from different angles.
5. Refractive Index: The refractive index measures how light is bent as it passes through the gemstone. Tanzanite typically has a refractive index ranging from 1.691 to 1.700. This property affects the gemstone’s brilliance and how light interacts with it, contributing to its overall appearance.
6. Specific Gravity: Tanzanite has a specific gravity ranging from 3.35 to 3.38. Specific gravity indicates the density of the gemstone compared to the density of water. This property helps gemologists distinguish Tanzanite from other similar-looking gemstones.
7. Cleavage: Tanzanite exhibits good cleavage, which means it can split along certain planes or directions. Gem cutters need to take this into account when shaping and faceting Tanzanite to minimize the risk of fractures.

Understanding the physical properties of Tanzanite is crucial for evaluating its quality, durability, and overall suitability for different jewelry applications. These properties, along with the gemstone’s remarkable color, contribute to its allure and desirability in the world of gemstones.

Optical properties

The optical properties of Tanzanite play a significant role in its visual appearance and overall beauty. Here are the key optical properties of Tanzanite:

1. Refractive Index: Tanzanite has a refractive index ranging from approximately 1.691 to 1.700. The refractive index determines how much light is bent or refracted as it passes through the gemstone. Tanzanite’s refractive index contributes to its brilliance and sparkle.
2. Pleochroism: Tanzanite is highly pleochroic, meaning it exhibits different colors when viewed from different crystallographic directions. In the case of Tanzanite, it displays a blue hue when viewed from one direction, violet from another, and sometimes even a burgundy color from a different angle. The pleochroic effect adds depth and interest to the gemstone’s appearance.
3. Birefringence: Tanzanite has a relatively high birefringence due to its orthorhombic crystal structure. Birefringence refers to the difference in refractive indices between two perpendicular crystallographic directions. In Tanzanite, this property can result in a doubling of facets or edges when viewed through the gemstone, a phenomenon known as doubling.
4. Dispersion: Tanzanite exhibits moderate to high dispersion, which refers to the ability of a gemstone to separate white light into its spectral colors or fire. The dispersion in Tanzanite contributes to the play of colors and adds to its visual appeal.
5. Transparency: Tanzanite is typically transparent to translucent, allowing light to pass through the gemstone with minimal obstruction. High-quality Tanzanite with good transparency allows for excellent light transmission, enhancing its brilliance and color display.
6. Luster: Tanzanite exhibits a vitreous to subadamantine luster, giving it a desirable and reflective shine. The gemstone’s luster adds to its overall attractiveness and visual appeal.

Understanding the optical properties of Tanzanite is crucial for gemologists, jewelers, and gemstone enthusiasts. These properties influence the way light interacts with the gemstone, affecting its color display, brilliance, and visual effects such as pleochroism and dispersion. It is these optical characteristics that make Tanzanite a captivating and sought-after gemstone.

Chemical composition

Tanzanite is a variety of the mineral zoisite, which belongs to the epidote mineral group. The general chemical formula for zoisite is Ca2Al3(SiO4)(Si2O7)O(OH). However, Tanzanite contains additional elements that give it its distinct blue-violet color. The blue coloration is primarily due to the presence of trace amounts of vanadium (V), while the violet color is attributed to the presence of chromium (Cr). The specific chemical composition of Tanzanite can be expressed as (Ca2Al3(SiO4)(Si2O7)O(OH)) with vanadium and chromium impurities

It’s important to note that the presence of these impurities, particularly vanadium and chromium, is responsible for the exceptional coloration of Tanzanite. The combination of these elements in the crystal lattice of Tanzanite gives it its unique blue and violet hues, which are highly prized in the gemstone world.

The chemical composition of Tanzanite provides valuable insights into its mineralogical classification and the elements responsible for its remarkable color. Understanding the presence of vanadium and chromium helps gemologists and scientists identify and distinguish Tanzanite from other similar gemstones.

Famous tanzanite jewelry pieces

There are several famous Tanzanite jewelry pieces that have gained recognition for their beauty, craftsmanship, and historical significance. Here are a few notable examples:

1. The Queen of Kilimanjaro:
   • The Queen of Kilimanjaro is one of the most famous Tanzanite jewelry pieces.
   • Created by renowned jewelry designer Michael Scott, this necklace features a 242-carat Tanzanite as its centerpiece.
   • The necklace also incorporates over 100 carats of diamonds set in platinum.
   • The Queen of Kilimanjaro was unveiled in 1988 and has since become an iconic representation of Tanzanite’s allure.
2. The Midnight Star:
   • The Midnight Star is an exquisite Tanzanite ring owned by actress Elizabeth Taylor.
   • The ring showcases a remarkable 116-carat cushion-cut Tanzanite surrounded by 16 carats of diamonds.
   • This stunning piece was gifted to Elizabeth Taylor by her husband Richard Burton and became a cherished part of her jewelry collection.
3. The Grandidierite Necklace:
   • Designed by Tiffany & Co., the Grandidierite Necklace features a rare 115-carat grandidierite gemstone as its focal point.
   • The necklace also incorporates Tanzanite gemstones, diamonds, and platinum.
   • The unique combination of the rare grandidierite gemstone and Tanzanite creates a captivating and distinctive piece of jewelry.
4. The Greenbrier Tiara:
   • The Greenbrier Tiara is a magnificent headpiece commissioned by the Greenbrier Resort in West Virginia, USA.
   • The tiara showcases several gemstones, including a large pear-shaped Tanzanite, surrounded by diamonds and set in platinum.
   • This regal and elegant tiara has become an iconic symbol of luxury and glamour.

These famous Tanzanite jewelry pieces have not only showcased the beauty and allure of Tanzanite but have also played a role in raising awareness and appreciation for the gemstone. They exemplify the exceptional craftsmanship and artistry that goes into creating exquisite jewelry pieces featuring Tanzanite as the centerpiece.