Discovering the secrets of tanzanite’s allure begins with understanding how to identify this precious gem.
Known for its striking blue-violet hues, tanzanite is a treasure nestled in the heart of Tanzania. You’re about to learn the key characteristics that set tanzanite apart from other gemstones.
Whether you’re a gem enthusiast or considering a tanzanite purchase, knowing how to spot the real deal is crucial. We’ll guide you through the nuances of color, clarity, and cut that make tanzanite so unique.
Get ready to become a savvy tanzanite identifier with these insider tips.
To identify genuine tanzanite, observe its distinct blue-violet hue and check for inclusions. Use a streak test for a white streak, confirm non-magnetism, and verify a Mohs hardness of 6.5-7. Tanzanite is singly refractive, shows birefringence, has a refractive index of 1.69-1.70, and a specific gravity of 3.10-3.38.
How to Identify Tanzanite Through Testing
Visual Inspection
Begin your tanzanite identification by thoroughly examining the gemstone’s appearance. Look for the signature blue-violet color, a definitive hallmark of tanzanite. Check for inclusions, which are typically found in natural stones, and be wary of any stones that appear flawless, as these may be synthetic or treated.
The Streak Test
The streak test is a simple way to examine the color of a mineral in its powdered form. Gently rub the tanzanite against a piece of unglazed porcelain tile and observe the color of the streak it leaves. Tanzanite should leave a white streak, indicating its authenticity.
Magnet Test
While tanzanite is not magnetic, impurities within the stone may respond to a strong magnet. Use a high-strength neodymium magnet to test your tanzanite. If the stone shows magnetic attraction, it might contain magnetic minerals, suggesting it is not pure tanzanite.
Hardness Test
Tanzanite ranks 6.5 to 7 on the Mohs scale of hardness. To perform a hardness test, try scratching the surface of the stone with a substance of known hardness. A simple method is to use a steel file, which, if unable to scratch your tanzanite, may confirm its authenticity.
Birefringence Test
Birefringence refers to a gem’s ability to refract two separate rays of light. Observe the stone under a polariscope or by using a doubly refractive filter. You should see doubling of the back facets or a doubling effect on the inclusions if it’s real tanzanite.
Checking The Diaphaneity
Examine the transparency of your tanzanite. It should be transparent to slightly translucent. Hold the gem up to a light and verify if light passes through effectively, which is characteristic of high-quality tanzanite.
Single or Double Refraction
Tanzanite is a single refractive gemstone, which is unusual for a colored stone. When placed under a gemological refractometer, you should not observe double refraction, unlike other minerals like calcite that have similar colors.
Refractive Index Test
Using a refractometer, measure the refractive index (RI) of the tanzanite. The expected RI of natural tanzanite ranges from 1.69 to 1.70. Deviation from this range could signal that the stone is not genuine tanzanite.
Finding The Specific Gravity
The specific gravity (SG) of tanzanite should be between 3.10 and 3.38. You can calculate the SG by weighing the gem in air and then suspended in water, using the formula SG = Weight in Air / (Weight in Air – Weight in Water).
Identifying Tanzanites in the Field
Spotting tanzanite in the field requires knowing its typical geological environment. Look for gemstone deposits within a metamorphic rock formation, where tanzanite is often found.
Recognizing Potential Tanzanite Rocks
Among the geographical clue, potential tanzanite rocks often have a noticeable blue-violet tint and a vitreous luster. They may also appear in elongated, columnar crystals or in a more granular form when mixed within the host rock.
Detecting real tanzanite demands careful observation and testing to distinguish it from simulants and treated stones. By following these testing methods, you’re on track to becoming proficient in identifying authentic tanzanite gemstones.
Physical Characteristics of Tanzanite
Recognizing the unique physical characteristics of tanzanite is crucial in its identification. Belying its delicate appearance, tanzanite rates between 6 and 7 on the Mohs scale of hardness. While this suggests a reasonable level of durability, you should remember it’s not as hard as diamonds.
Distinct color variations set tanzanite apart. It typically showcases a remarkable range of blue and violet hues. Under different lighting conditions, you may observe it shifting from a deep blue to a vibrant violet. This pleochroic nature is a telltale sign of authentic tanzanite.
The stone’s cleavage, which is perfect in one direction, means it’s prone to chipping if not handled with care. Tanzanite’s crystal structure is orthorhombic, forming in elongated, columnar shapes. This aspect isn’t always visible to the naked eye but becomes apparent under magnification.
When examining potential tanzanite stones, look out for inclusions. While some inclusions are considered normal, a visually flawless tanzanite is rare and often an indicator of high quality. Inclusions can take various forms, from small crystals to feathers and should be examined with scrutiny.
Density, another measurable attribute, also provides insights. Tanzanite exhibits a specific gravity ranging from 3.10 to 3.38, which distinguishes it from many other gems.
Thorough knowledge and examination of these physical properties are essential when verifying the genuineness of tanzanite. With these checks, you’ll be better equipped to assess a suspected stone’s authenticity.
How Are Tanzanite Formed?
Tanzanite’s formation is a tale of geological wonder that goes back millions of years. Deep in the earth’s crust, under conditions of intense heat and pressure, tanzanite originates from a mineral known as zoisite. Only one place on Earth has the perfect storm of conditions necessary for this transformation – the Merelani Hills of Northern Tanzania.
Under these extreme conditions, vanadium ions incorporate into the zoisite mineral structure and cause the distinct blue-violet hue that tanzanite is renowned for. The presence of vanadium is critical, as it’s the trace element that gives tanzanite its color. When the conditions are just right, zoisite crystals transform into the tanzanite gemstones treasured around the globe.
The process is complex and requires a specific sequence of temperature and pressure changes over time. This includes cooling periods that must occur slowly enough to preserve the crystal structure but quickly enough to lock in the color. These geological processes culminate in the formation of the tanzanite crystals:
- Unique Geology: The area where tanzanite forms is rich in graphite and other metamorphic rocks.
- Temperature and Pressure: Temperatures exceeding 600 degrees Celsius and pressures above 5 kilobars are needed to form tanzanite from zoisite.
- Cooling Period: Rapid cooling can alter the crystal structure, so moderate cooling is necessary for quality tanzanite.
Understanding these geological factors is integral to recognizing why tanzanite is so rare and valuable. Moreover, it facilitates a greater appreciation of the arduous journey each gemstone undergoes from its raw mineral state to the stunning piece of tanzanite jewelry in your collection.
Preparation for Tanzanite Hunting
Gathering the Right Tools
When venturing out to hunt for tanzanite, having the right tools is crucial. You’ll need a geologist’s hammer for breaking rocks and a chisel to help pry apart potential finds. Bring along a strong magnifying glass or a jeweler’s loupe because you’re going to need to take a close look at rock patterns and crystal structures.
Here’s what to pack:
- Geologist’s hammer
- Chisel
- Magnifying glass or jeweler’s loupe
- Hardness test kit
- Field guide on minerals
Remember, the quality of your tools can greatly impact your ability to properly identify tanzanite in the field. Investing in good quality, durable equipment will pay off when you’re sifting through various minerals and rocks.
Safety Considerations
Safety should never be an afterthought. Protective gear is a must, as is notifying others of your location. You’re advised to wear safety goggles when chipping away at rocks to prevent flying debris from causing eye injury. Durable gloves can protect your hands from sharp edges and rough materials.
Here’s a safety checklist:
- Safety goggles
- Durable gloves
- Sturdy footwear
- First aid kit
- Sufficient water and snacks
- Communication device
Always tell someone where you’re going and, if possible, hunt with a partner. Staying hydrated and nourished is important, as is having a fully charged phone or radio in case of emergencies. Being well-prepared ensures that your tanzanite hunting is not only successful but also safe.
Handling and Care of Found Tanzanite
Once you’ve found a piece of tanzanite, it’s crucial to handle it with care to maintain its condition and value. Tanzanites, like other gemstones, require specific care to keep them looking their best. The following guidelines will help you clean and store your tanzanites properly.
Cleaning Tanzanites
Cleaning your tanzanites correctly is essential to preserving their vibrant blue-violet hue. Remember that tanzanite is relatively soft compared to other gemstones, so handle it gently.
- Use a mild soap solution and a soft-bristled brush to gently scrub the tanzanite.
- Rinse the gemstone thoroughly with lukewarm water to eliminate any soap residue.
- Avoid using harsh chemicals or ultrasonic cleaners, as these can damage the stone.
- Pat the tanzanite dry with a lint-free cloth, taking care not to apply too much pressure.
By keeping your tanzanite clean, you ensure its luster and clarity remain intact, highlighting its exquisite beauty.
Storing Tanzanites
Proper storage is just as important as cleaning to protect your tanzanite’s structural integrity and visual appeal.
- Store your tanzanites separately to prevent scratching. Tanzanite is less hard than many other gemstones, so contact with harder substances can cause damage.
- Wrap tanzanites in soft cloth or place them in a fabric-lined jewelry box.
- Keep the stones in a cool, dry location away from direct sunlight, which can cause fading over time.
When storing multiple pieces of tanzanite, consider the following:
- Individual compartments or padded slots in a jewelry box are ideal for keeping stones separated.
- For extra security, use sealable plastic or felt bags to contain each stone.
Remember that proper storage is fundamental to maintaining the quality and value of your tanzanites. Avoiding contact with other jewelry minimizes the risk of nicks and scratches, ensuring your gems stay dazzling for years to come.
Conclusion: Confirming Tanzanite is Real
Armed with the know-how to test and identify tanzanite, you’re now set to confirm your find with confidence.
Remember to observe carefully and conduct thorough testing to ensure authenticity. Don’t forget the significance of proper handling and care to maintain your tanzanite’s sparkling allure. By storing it correctly and cleaning it with a gentle touch, you’ll preserve its beauty and value for years to come.
With these insights, you’re ready to appreciate the true charm of tanzanite, whether you’re adding to your collection or selecting a gem for its aesthetic appeal.
