Spinel, the gemstone that’s been masquerading as some of the most famous rubies in history, is finally stepping into the spotlight.

You’ve probably heard its name, but can you tell a spinel from a ruby or sapphire? It’s not as hard as you might think.

With its range of stunning colors and its remarkable resemblance to more well-known gems, spinel is a true chameleon in the world of gemstones. Knowing how to identify a real spinel can save you from a costly mistake and add a unique piece to your collection.

Let’s dive into the key characteristics that set spinels apart.

Identifying real spinel involves visual inspection for octahedral shape, white streak test, magnet test for iron content, scratch test for hardness of 7.5-8, checking for absence of birefringence, confirming diaphaneity, single refraction verification, refractive index of 1.712-1.762, and specific gravity of 3.5-4.1.

How to Identify Spinel Through Testing

Visual Inspection

You’ll want to start with a keen visual inspection. Spinel crystals are usually octahedral in shape. Look for this along with smooth planes and lack of cleavage. The color range can be your first clue—spinel comes in a variety of shades, but beware, color alone won’t confirm its identity.

The Streak Test

Perform the streak test by dragging the gemstone across an unglazed porcelain plate. A true spinel will leave a white streak regardless of its appearance. This simple test can be quite telling and is easy to conduct with minimal equipment.

Magnet Test

Interestingly, some spinel varieties are magnetic due to iron content. Pass a strong magnet near the stone; if it’s magnetic, you could be holding spinel. Keep in mind, not all spinels will respond to this test.

Hardness Test

Utilize a scratch test to determine hardness. Spinel ranks 7.5 to 8 on the Mohs scale. Test this by trying to scratch the gem with substances of known hardness. A genuine spinel will scratch glass with ease, noting its notable hardness.

Birefringence Test

Unlike some gems, spinel is not birefringent. If you’re viewing double images through the stone under magnification, it’s not a spinel. This test requires a loupe or microscope to observe the stone’s optical properties accurately.

Checking The Diaphaneity

Examine the stone’s transparency, otherwise known as diaphaneity. Spinels range from transparent to opaque. A transparency test helps assess if the stone’s light transmission characteristics match those of spinel.

Single or Double Refraction

Spinel is a singly refractive gem, meaning light travels through it at a constant speed regardless of its path. In comparison, other stones like a ruby are doubly refractive. View the stone under a polariscope to check for this property.

Refractive Index Test

Conduct a refractive index test using a refractometer. The refractive index of spinel lies typically between 1.712 and 1.762. Values significantly outside this range suggest the stone might be an imposter.

Finding The Specific Gravity

Specific gravity measurements can help identify spinel. The typical range for a spinel is about 3.5 to 4.1, differing from other stones with a similar appearance. Specific gravity scales or hydrostatic balances can be used for this test.

Identifying Spinels in the Field

Spotting spinels in their natural environment often requires a practiced eye. Search for well-formed octahedral crystals and remember, spinels can be found in gravel or alongside other gemstones like sapphires.

Recognizing Potential Spinel Rocks

In the field, spinels are often nestled in marble or calcite. Look for rocks with these traits or in geologically relevant locations such as Myanmar, Sri Lanka, and Vietnam where spinel deposits are common.

When you’re trying to determine if you’ve found a spinel, each test you conduct narrows down the possibilities, leading you closer to the definitive identification of your gemstone. Keep in mind, though, that professional testing is always recommended to confirm the true identity of your find.

Physical Characteristics of Spinel

When you’re on the hunt for spinels, familiarizing yourself with their physical traits is vital. Spinel gems exhibit a wide range of colors, from vibrant reds and hot pinks to cool blues and purples. The cause of this color variety is the presence of trace elements such as iron, chromium, and vanadium. Unlike some gems, spinels are singly refractive, which means they maintain the same color intensity from different angles.

The hardness of spinels is another distinguishing feature. They score an impressive 8 on the Mohs scale of mineral hardness, making them durable and resistant to scratches. This attribute also helps in distinguishing spinels from other stones which may look similar but have a lower hardness.

Spinel crystals tend to form in isometric system, typically found as octahedral crystals. These well-formed crystals can often be a tell-tale sign you’re dealing with a true spinel. Some spinels may also exhibit fluorescence under ultraviolet light, presenting a captivating display that can aid in their identification.

Understanding the physical characteristics of spinels, like color ranges and crystal formations, is an integral part of the identification process. It not only helps in recognizing them in their raw form but also adds to your ability to appreciate their beauty and significance in the gemstone world. Keep this knowledge in hand as you examine potential spinels and remember to factor in all aspects of their physical makeup.

How Are Spinel Formed?

To understand how to identify a spinel, you’ll need a grasp on how they’re formed. Spinel crystals develop in the earth’s crust, typically through metamorphic processes. They’re often found in rocks such as marble and gneiss, originating from a transformation that occurs under intense pressure and high temperatures. These conditions allow for the growth of those distinctive isometric crystals you’ve learned to look for.

Remarkably, spinels can also form from the cooling of magma. This igneous process explains why they are sometimes discovered in geological formations alongside sapphire and ruby. It’s the underlying chemistry during formation that determines the vast color range you see in these gemstones. Impurities within the mineral structure, like chromium, iron, and cobalt, are what give spinels their vibrant reds, pinks, blues, and even purples.

Moreover, understanding that spinels form in layers within the earth helps explain their hardness and durability. As part of your identification toolkit, remember that these gems are born from harsh conditions, which contributes to their impressive endurance and why they often don’t show signs of wear – a trait that’s rare in softer gemstones.

Preparation for Spinel Hunting

When you’re ready to embark on a spinel hunting adventure, preparation is crucial. This means equipping yourself with the right tools and knowledge to identify these gemstones in the wild. A well-prepared hunter is not only more likely to find spinels but can also do so safely and efficiently.

Gathering the Right Tools

Before stepping out into the field, ensure you have the necessary equipment. Proper tools can make the difference between a fruitful search and a fruitless excursion. Here are items you shouldn’t leave home without:

  • Magnifying glass: To inspect potential spinel finds closely.
  • Geologist’s hammer: For carefully extracting specimens.
  • Tweezers: For picking up small crystals.
  • Streak plate: To conduct the streak test on the go.
  • Magnet: As some spinel varieties are magnetic.
  • Notebook and pen: To record the location and characteristics of your findings.
  • Safety gear: Including gloves and goggles.
  • Sturdy container: To transport your spinel treasures.

Remember, the right tools not only aid in identification but also protect the integrity of the specimens you collect.

Safety Considerations

While the thrill of discovery can be intoxicating, never overlook your safety. Spinel hunting might lead you to remote areas with various hazards. Here’s how to stay safe:

  • Always inform someone about your planned location and return time.
  • Wear appropriate clothing, including long pants and durable boots.
  • Stay aware of the wildlife and plants in the area to avoid harmful encounters.
  • Bring a first aid kit in case of minor injuries.
  • Be cognizant of the terrain and weather conditions to prevent accidents.
  • Hydration is key; carry sufficient water for the duration of your hunt.
  • If you’re not familiar with the area, consider hiring a local guide.

By taking these precautions, you’re setting yourself up for a successful and enjoyable spinel hunting experience. Remember, your well-being is paramount—gems are abundant, but there’s only one of you. Keep your safety at the forefront as you scour nature’s bounty for these precious stones.

Handling and Care of Found Spinel

After identifying and safely acquiring spinels, it’s essential to know how to handle, clean, and store these gems properly. Proper care ensures that your found spinels maintain their luster and prevents potential damage.

Cleaning and Storing Spinels

When it comes to cleaning spinels, you want to be as gentle as possible. Avoid harsh chemicals and opt for a mild soap with lukewarm water. Here’s a step-by-step guide:

  • Use a soft brush to remove any dirt or debris from the spinel.
  • Prepare a solution of warm water and mild soap.
  • Soak the spinel in the solution for about 15 minutes.
  • Gently brush the stone again while it’s submerged.
  • Rinse the spinel with clean water to remove any soap residue.

Once the spinel is clean, pat it dry with a soft, lint-free cloth. Avoid using paper towels as they might scratch the surface.

For storing your spinels, individual soft pouches or a jewelry box with a padded interior are ideal. Ensure each spinel is separated to prevent scratching or damage from contact with other stones or hard surfaces. If you’re planning on transporting your spinels, invest in a case designed for transporting gemstones, providing additional protection against impacts and temperature changes.

Remember, spinels are durable but can still suffer from mishandling. Always handle your gems with care, protecting them from sharp blows and extreme pressure, which could cause chipping or cracking. By following these simple care guidelines, your spinels will retain their beauty for years to come.

Conclusion: Confirming Spinel is Real

Mastering the art of identifying spinel ensures that you’ll recognize the true value of your find.

With the knowledge of their distinct characteristics and proper care techniques, you’re now equipped to handle these precious gems with the expertise they deserve. Remember, the beauty of spinel lies not just in its vibrant colors but also in its durability. Treat your spinels with the gentle touch they require, and they’ll remain a stunning part of your collection for years to come.

Keep exploring and trust your newfound skills to distinguish these treasures with confidence.

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