Everything you need to know about Spinel Gemstone
Spinel wasn't well known among consumers until lately and was a poorly regarded jewel. However, the rising need for ruby substitutes has revitalised interest in Spinel, with its distinctive red hue and lengthy history.
In ancient times, the mines of southeast Asia produced excellent giant spinel crystals that were the prized possession of kings and emperors, often changing hands due to warfare. Due to its similarity to ruby and other precious stones, Spinel has played a significant role in jewellery throughout history.
The Black Prince's Ruby and the Timur Ruby in the British Crown Jewels are excellent examples of enormous red spinels (ruby spinel). This gemstone was originally called Balas ruby in history.
Description
Spinel has been a popular gemstone in jewellery for thousands of years, but it has only just begun to receive the acclaim it truly deserves. Spinel and corundum were often mistaken before modern gemology in the late 19th and early 20th centuries because they were found in the same mines.
However, there are chemical differences between these minerals. As a result, the reputation of the Spinel took a hit after jewellers had to tell customers that some of their prized rubies and sapphires were spinels.
Spinel has the same physical properties in all crystal directions, like diamond and garnet. As a member of the cubic crystal system, its most common crystal shape is an octahedron, which resembles a pair of pyramids placed back-to-back. As a result, spinel crystals in good shape can be found in nature quite frequently.
In addition to octahedral crystals, Spinel can create flattened crystals with a distinct appearance. When an octahedron grows, the pyramids that make up its shape spin against one another, resulting in a flattened shape.
The scientific community refers to this as a "twinned crystal." In general, large gems cut from good-colour twinned crystals are shallow. Thus the attractiveness of such a stone should not be evaluated just by its size.
The jewellery-grade Spinel is just one member of a family of minerals with a similar crystal structure. However, not all of them can grow into beautiful jewellery-grade crystals. Spinel is available in many different colours, from orange to vivid "stoplight" red, from bright pink to every shade of purple, blue, violet, and bluish-green.
Chromium oxide causes bright pinks and reds. If the percentage of chromium in an object is high enough, its colour will be a deeper red. Therefore, combining iron and chromium gives orange and purple stones their colour.
Moreover, Spinel's hue ranges from violet to blue depending on the presence or absence of iron, and the intense blue colour comes from traces of cobalt.
Facts
| Absorption Spectrum | Enhancement | Etymology |
| Red and pink; intense fluorescence between 490 and 595 nm; a faint band at 656 nm; and distinct lines at 685.5 and 684 nm. It might also exhibit a chromium spectrum, a wide band at 540 nm, and violet absorption. Violet and purple may exhibit the same spectrum as blue but with a weaker signal. | Spinels that are naturally occurring may be heated but are typically not improved. It is possible to quench crackling synthetic spinels. | Perhaps the Latin word spina, which means "thorn," alludes to crystals with spine-like shapes. However, this genesis is unknown because Spinel does not often behave in this manner. |
| Birefringence | Birthstone | Cleavage |
| None | August | None |
| Colour | Crystallography | Dispersion |
| red, orange, pink, purple, blue, black | Isometric. Crystals are octahedral; also, as grains, massive. | 0.02 |
| Formula | Fracture | Fracture Luster |
| MgAl2O4 + many substitutional elements. | Conchoidal | Vitreous to subadamantine. |
| Identifying Characteristics | Luminescence | Occurrence |
| Small octahedral crystals in Spinel are frequently oriented in swirls or planes. Strong ADR synthetic spinel with cross-hatching. Except for red and pink, fluorescence frequently deviates from natural. | Pinks and reds: no phosphorescence; crimson in LW and SW; red in X-rays. Blue: UV-inert. Deep purple: violet in X-rays, red in LW, and completely inactive in SW. Pale blue and violet: X-rays and LW are green; SW is practically inactive. Inert to weak red or red/orange SW; orange, red, and pink colours. Strong to weak red and orange LW Cobalt blue; bright, pale green in the southwest. LW that is neutral to slightly orange or orange/red. Light green and almost colourless; neutral to mild orange/red LW Deep purple; inactive SW; red LW. Violet and pale blue; green LW, inactive SW. | Metamorphic rocks and the byproducts of their weathering contain Spinel. Very prevalent in contact deposits (marbles and limestones). |
| Heat Sensitivity | Luminescence Present | Luminescence Type |
| No | Yes | Fluorescent, UV-Long, UV-Short, X-ray Colours |
| Lustre | Mineral | Mohs Hardness |
| Vitreous | Spinel | 7.5-8 |
| Optics | Phenomena | Pleochroism |
| Isotropic | Asterism, chatoyancy, colour change (rare). | None |
| Polish Luster | Refractive Index | Specific Gravity |
| Vitreous | Varies, 1.719-1.920. | 3.58-3.98; gems 3.58-3.61. |
| Transparency | Typical Treatments | Varieties |
| Transparent to opaque | Heat treatment | Ceylonite, Chromite, Gahnospinel, Hercynite, Pleonaste |
| Variety of | Wearability | |
| Best Known Gemstones | Excellent |
History
Spinel is among the most undervalued gemstones in history. Yet, some of the same mines that furnished rubies and sapphires to ancient royal courts in Rome and China also yielded Spinel.
Ancient times saw giant spinel crystals emerge from the mines of central and southeast Asia. However, Balas rubies were so rare and valuable that they were prized possessions of emperors and kings and frequently changed hands as war booty. Some of the world's most prestigious "rubies" are Spinel.
"Black Prince's Ruby" is one of the most well-known instances. The Imperial State Crown of England, which includes this old ruby, is on exhibit in the Tower of London. This diamond, which is octagonal and has high brilliance, is the yield of Afghan mountains.
The fourteenth century saw the first written mention of the stone. After successive Moorish and Spanish kings, it was awarded to Edward, Prince of Wales, the "Black Prince," in 1367 as a prize for a victorious military expedition.
Several subsequent English rulers, most notably Henry VIII, held the jewel in high esteem. Together with the Koh-i-Noor diamond, it is one of England's crown jewels that has withstood the test of time, including fires, attempted thefts, and World War II bombing strikes.
The 'Timur ruby,' another massive spinel in the Crown Jewels, is more than 350 carats. Its past is just as tumultuous. However, several carved Persian inscriptions confirm the gem's antiquity.
The public's lack of clarity on Spinel is likely due partly to modern technological advancements. This is mainly because synthetic Spinel is a popular substitute for various genuine gemstones. Most buyers have no idea that the stone also occurs in nature.
Stone Sizes
Spinels come in a wide range of colours and can weigh hundreds of carats.
- The Smithsonian Institution in Washington, DC, has these colour codes: 45.8 (light purple, Sri Lanka); 36.1 (indigo blue, Myanmar); 34 (red, Myanmar); 29.7 (pink-violet, Sri Lanka).
- Deformed red octahedron from Sri Lanka, 520; another crystal, 355. Both are on display at the British Museum of Natural History in London, England.
- A Private Collection, 11.25 (Sri Lanka, superb cobaltian gem, intense blue emerald-cut).
- Fine red gem, number 105, from the Louvre in Paris, France.
- Statistics from New York's American Museum of Natural History: 71.5 (red, Sri Lanka).
- Black Prince's Ruby, a red spinel valued at 170 million pounds; Timur Ruby, a red spinel valued at 361 million pounds; both are part of England's Crown Jewels.
- Fine red diamond, over 400 carats, at Diamond Fund, Moscow, Russia.
- Red stones worth around 500, another over 200, and one around 225 are at the Banque Markazi in Teheran, Iran.
Stone Care
Spinels are tough gemstones that don't need additional treatment to keep them looking their best. Warm soapy water is always a safe option for cleaning Spinel. Some spinel may go through a heating process that will affect its hue. The treatment won't fade or peel under regular use. Like other transparent gemstones, Spinel may be fracture-filled to enhance its apparent clarity.
FAQs
1. Is Spinel an expensive gem?
Compared to the hefty price tag of a single ruby carat, which might be anywhere from $57,143 AU to $114,286 AU, the going rate for a comparable quality spinel is a mere $1,428 AU to $10,000 AU. This is supposedly the more cost-effective option.
2. Is Spinel a rare gem?
Class rings and birthstone jewellery frequently include counterfeit gemstones, which has tarnished the public's perception of the real thing. However, genuine Spinel has always been a precious gem that is hard to find.
3. What colour spinel is the most expensive?
Different shades of Spinel are rarer and more expensive than others. The most sought-after gemstones are red, beautiful cobalt blue, intense hot pink, and vivid orange stones. Compared to other, rarer colours, violet and bluish purple to purple or lavender, stones are typically less desirable and in lower demand.
4. What are the healing properties of Spinel?
Spinel is known as the "rejuvenation gemstone" because of its reputation for helping its user feel renewed physically, mentally, and emotionally. It has a relaxing impact on the body and mind thanks to its restorative powers. This makes it an excellent gemstone for people whose jobs need them to put in lengthy, physically demanding shifts.