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December’s birthstone Tanzanite


Tiffany and Co. called it “the loveliest blue gemstone discovered in over 2000 years”, so here’s hoping you find some jewellery featuring December’s birthstone Tanzanite under the tree this Christmas.

December's birthstone Tanzanite
December’s birthstone Tanzanite

Though Tanzanite is simply a blue form of the gemstone zoisite, ‘blue zoisite’ was thought rather a dull name for such a sparkling beauty.  Tiffany & Co, who owned the mines, needed a name more likely to catch the imagination of the consumer, and so Tanzanite was born – named after Tanzania, the African country that holds the world’s only known source of gem-quality Tanzanite.

Discovered by a Masai tribesman in 1967, Tanzanite is a very young gem in commercial terms.  Nevertheless, it has achieved spectacular success and is now the most popular blue stone after sapphire.

Tanzanite occurs in various shades of blue ranging from the deep violet blue to a much lighter hue.  The bluer, richer end of this spectrum is the most valuable.   Most Tanzanite on the market has been heat treated to achieve this strong colour and a naturally deep blue stone will be very expensive. 

Its mesmerising colour is not the only thing that makes December’s birthstone special.  It is what gemmologists call a ‘phenomenal’ gemstone – a gemstone with interesting optical properties.  Tanzanite is pleochroic, which means its crystal structure displays different colours depending on the angle from which it is viewed.  A skilled gem cutter can cut a Tanzanite to take advantage of this.

At 6.5 on the Mohs scale of hardness, Tanzanite is not a stone for everyday rings and bracelets but is more suited to occasion wear or earrings and necklaces that won’t be subject to knocks and scratches.  You should always store each of your gemstone jewellery pieces in its own box or compartment, but this is particularly important for relatively soft gemstones like Tanzanite, which is easily scratched by many harder popular gemstones.

Tanzanite was discovered too recently to have acquired the mythology and lore that other gemstones have, but advocates of crystal therapy say that Tanzanite is a stone of spiritual growth and promotes psychic power.

Photo credit and thanks to: Featured is a stunning tanzanite cut by Jeff Hapeman for SITR. Acquired from purple gemstone hoarder, Don Johnson. This gem now resides in a custom ring by Lindsay Jane and will be revealed later in 2020.

Kim Rix GG GIA

Gemstone Detective

Be sure | Be smart | Buy with confidence

November birthstone: Topaz


Though the weather is turning dull and grey, November babies can rejoice in the rainbow of colours their November birthstone, topaz, offers.  Did you know, though, that the popular ‘Swiss blue’ or ‘London blue‘ colour you’ll see in the jeweller’s shop window is almost always caused by heat treatment and doesn’t often occur naturally?

November birthstone Topaz |

Occurring as a colourless stone as well as in shades of pink, purple, yellow, brown, orange, green and blue, Topaz is allochromatic.  Allo-what?  Well, allochromatic means that the colour variations are caused by impurities or defects in its chemical structure. 

Topaz, is also pleochroic, which means that it will display different colours when its crystal structure is observed from different angles. This pleochroism is especially true of the pink to red topaz as seen in this GIA video.

Of all the colours, the most expensive is referred to as Imperial Topaz.  This whisky-coloured stone with hints of pink is now mined in Brazil, but was originally mined in Russia’s Ural Mountains and named in honour of the Russian royal family.  At that time, Imperial Topaz was so prized that only the Russian royals were allowed to own it.

Topaz is so called because of a tiny island in the Red Sea.  Now called Zabargad, in ancient times it was known as Topazios and famed for the gemstone…erm, peridot.  Wait, what? Rather confusingly, the ancients thought that peridot and topaz were one and the same.  It wasn’t until the early 18th century that topaz and peridot were distinguished from each other.

As well as being a November birthstone, topaz is also used to ease many mental and physical ills.  When worn as a necklace, topaz was believed to dispel enchantment, bring wisdom and chase away depression.  The ancient Greeks thought it could increase strength on the battlefield, detect poisons and even turn its wearer invisible.  Mixed with wine, topaz was considered a cure for burns, haemorrhages, insomnia and respiratory difficulties—perfect for those winter coughs and colds! 

Photo credit: 17.01ct Brazilian Imperial Topaz and diamond bangle bracelet featuring bezel set Burma rubies on sides as accent gems. Bracelet is crafted in 18kt yellow gold and designed by Shelly Sergent for Somewhere In The Rainbow Collection. Crafted by Seam Ryan.

Kim Rix, GG GIA

Gemstone Detective

Be sure. Be smart. Buy with confidence

October’s birthstone: Tourmaline


Welcome to the world of tourmaline in part 2 of October’s birthstone blog!

October's birthstone tourmaline |


Tourmaline gets its name from a Sinhalese phrase ‘tura mali’, which means ‘stone mixed with many colours’ in this native language of Sri Lanka.  The presence of different elements in tourmaline’s makeup produces its plethora of colour variations.  A tourmaline rich in iron will be black, blue-black dark brown and one rich in magnesium will be mid-brown to yellow one.  Add lithium, though, and the sky’s the limit – the presence of lithium can produce a tourmaline of almost any colour! 

Many tourmalines have more than one colour within the same stone.  Watermelon tourmaline is the best known of these varieties and, as the name suggests, occurs in green and pink layers that look almost good enough to eat!

If the choice of colour isn’t enough to pique your interest, how about tourmaline’s optical properties?  Some tourmalines seem to change colour under different light sources and some display chatoyancy, which gives them the appearance of a cat’s eye.

Let’s not forget tourmaline’s interesting chemical properties either.  Famous 19th century art critic and polymath John Ruskin once described the chemical makeup of tourmaline as being ‘more like a doctor’s prescription than the making of a reputable mineral’!   Swedish botanist Carl Von Linne described tourmaline as ‘the electric’ stone because it acquires an electrical charge when rubbed, attracting small particles like dust.  Well, that might make the weekly clean a bit more interesting!

October’s birthstone has many traditional uses, too.  Long considered to be a stone useful to those in creative industries, a tourmaline would make a lovely personal gift for an author, artist or designer.

Tourmaline is also believed to have health-giving and healing properties.  It was once thought that tourmaline had the power to induce sleep in feverish patients.  Modern-day crystal healers often use tourmaline to promote vitality and vigour in those they treat.  It’s said that some athletes have reported faster recovery from intense workouts when using the stone.

Just in case you missed it, here’s part 1 of this month’s birthstone blog to learn all about opal!

Kim Rix, GG GIA

Gemstone Detective

Be sure. Be smart. Buy with confidence

October’s birthstone: Opal


All you lucky October babies have not one but two stunning birthstones to choose from: opal and tourmaline.  

October’s birthstones are chemically very different, but they do have something special in common –both are stones of the rainbow in the mythology, folktales and lore of many cultures.  It’s not hard to see why, as opal and tourmaline are found in myriad colour variations. In the first of October’s blog posts, let’s take a closer look at opal.

Octobers birthstone opal |

How on earth can I begin to describe the beauty of an opal?  Roman natural historian Pliny the Elder had the same problem two thousand years ago, writing that ‘of all precious stones, it is opal that presents the greatest difficulties of description, it displaying at once the piercing fire of ruby,  the purple brilliancy of amethyst, and the sea-green of emerald, the whole blended together and gleaming with a brightness that is quite incredible.’

It’s difficult to argue with that!  Every opal is different, and even the individual patterns and colours within each stone change according to the light and viewing angle.  Finding the right opal is so personal that it is often said that the opal chooses you, rather than the other way round.

October's birthstone opal |
Stunning Opal

There has been a lot of research about the formation of opal. There is no definite or conclusive evidence as to how opal is formed. They are all theories and there’s a lot of conjecture. Nobody can prove exactly why or how opal has formed.

The vast majority of the world’s precious opal is mined in Australia and, of all the country’s opal mining localities, Lightning Ridge is probably the most famous. It’s here that the coveted ‘black opal’ is mined—a stone with a dark base colour that beautifully emphasises the multi-coloured flashes and patterns within.

Boulder Matrix Opal |

It’s the brilliance and vibrancy of these flashes of colour that determine an opal’s value.  Red is the most desirable colour, but brighter flashes of blue and green are more valuable than a dull red.  Generally, an opal displaying many different colours will fetch more than an opal with only one or two.

It’s no surprise that the mystical appearance of October’s birthstone has is associated with some incredible legends.  One such story from the Aboriginal tribes of southern Australia tells how the dreamtime creator transported himself to earth in a rainbow.  The place where he first touched the earth became a great plain of glittering stones in all the colours of the rainbow that had once rested there.

October’s birthstone has for thousands of years been associated with good fortune, prophecy and protection from harm, but it is also once believed to have been a stone used by witches—an association that means some people view opal as a symbol of bad luck.

Me?  I think that anyone who owns such a beautiful stone must be blessed with the best of luck!

If you want to find out more about identifying, choosing and buying an opal, take a look at the Gemstone Detective Series, Buying Gemstones and Jewellery in Australia.  You don’t have to be planning a trip down under to learn all you need to know about finding your perfect opal!

Next week, we’ll take a look at tourmaline.

Kim Rix GG (GIA)

Gemstone Detective

Be sure. Be smart. Buy with confidence

September’s birthstone: Sapphire


September’s birthstone is sapphire.  If you’re a September baby, then lucky you – regal and stylish, there’s a variety of this gorgeous gemstone to suit everyone.

September's birthstone sapphire |

The word sapphire comes from the ancient Greek sappheiros meaning ‘blue’, which itself comes from a Hebrew word meaning ‘precious gem’ and possibly from a Sanskrit word meaning ‘dark coloured’. 

It’s probably the case that when someone says ‘sapphire’, you think of a deep blue gemstone, but did you know that sapphires occur in many different colours?   With blue, pink, green, yellow, orange, purple, black and even colourless to choose from, you won’t be stuck for a sapphire to match your favourite outfit.

September’s birthstone doesn’t come in red, though, and that’s because red sapphires are actually…rubies!  Both sapphire and ruby are varieties of the mineral corundum and all corundum’s various colours are caused by different chemical elements within it.  For example, titanium and iron in the corundum give rise to an intense blue sapphire, and trace amounts of vanadium produce sapphires of a purple hue.

September's birthstone sapphire |

After blue sapphires, the padparadscha is the most prized ‘fancy’ sapphire.  Padparadscha means ‘lotus flower’ in Sinhalese, one of the native languages of Sri Lanka and was named because the gem has the same gorgeous salmon-pink colour of the blossom. 

Corundum is the second hardest mineral after diamond—9 on the Mohs scale of hardness—which makes it a great choice of gemstone to wear in rings that are prone to knocks and scratches

If you’ve chosen sapphire for an engagement ring, you’re in famous company.  The Duchess of Cambridge, Kate Middleton, wears the engagement ring that famously once belonged to Diana, Princess of Wales—a 12-carat, cornflower-blue sapphire surrounded by diamonds. Princess Eugenie’s engagement ring too, is a sapphire – a stunning, peach-coloured padparadscha.

Another reason to slip a sapphire on your beloved’s finger is that sapphire symbolises fidelity and sincerity when used in an engagement ring!

Star sapphire |

Sapphire can occur as a phenomenal gemstone—a gemstone that displays certain optical effects. A sapphire with asterism (a so-called ‘star sapphire’) will seem to have a six-rayed star floating across the surface of the stone; a colour-change sapphire will appear to turn another colour in different lighting conditions and a bi-coloured or ‘parti’ sapphire (typically found in Australia) displays two colours within the stone regardless of the light source.   

September's birthstone |

Not only September’s birthstone, sapphire is also the traditional gift for a 45th wedding anniversary and a 65th jubilee. 

Some practitioners of alternative therapies use sapphire to promote the immune system and impart clarity and wisdom to their patients.  Whether or not you believe in the healing properties of gemstones, September’s birthstone certainly makes it a wise choice!

Kim Rix, GG (GIA)

Gemstone Detective

Be sure. Be smart. Buy with confidence

August’s birthstone: Peridot


Peridot is not as well known as some gemstones, despite being August’s birthstone and the gemstone for a 15th wedding anniversary.  I think this beautiful green gemstone deserves much wider fame!

August's birthstone

The name peridot originally comes from the Arabic word ‘faridat’, which means ‘gemstone’, via the old French word ‘peritot’.

A variety of the mineral olivine, beautiful green peridot is one of very few gemstones that occur in one colour only.  The precise hue depends on the amount of iron present in the crystal structure, and can range from a bright, citrusy shade of green to a deeper, grassier colour. 

Formed deep underground, peridot is brought to the earth’s surface during volcanic eruptions.  Because of this, peridot gems are associated with Pele, goddess of volcanoes in Hawaiian culture.  

The peridot crystals themselves are found as nodules (solid, rounded masses of crystals) or as veins within igneous rocks such as basalt. 

Peridot is also associated with meteor crash sites and scientists have even discovered peridot in mineral samples gathered by space probes near the sun.  For this reason, August’s birthstone is sometimes referred to as the extra-terrestrial gemstone, making it the perfect gift for sci-fi fans!

Beloved of the Egyptians, peridot was first discovered on the Egyptian island Zagbarad (known in ancient times as ‘Topazios’) and is mentioned both in the bible and the writings of Roman natural historian Pliny the Elder.  Peridot is also mined in Myanmar, the USA, China, Africa and Australia, though the finest specimens are found on the border of Pakistan and Afghanistan.

In the 1900s, an enormous deposit was found in a mountain pass in Pakistan, 4,000 metres above sea level – so high up that mining can only take place in the summer months.  Peridot from these mines is often sold as ‘Kashmir peridot’ to indicate that its fine quality matches that of Kashmir sapphires.

Its clarity makes peridot a sparkly gem — perfect for parties and occasion jewellery.  Perhaps  this quality is the reason that peridot is referred to as the ‘stone of light’.  The Egyptians called it ‘the gem of the sun’.

Probably also due to its clarity, August’s birthstone has long been believed to ward off nightmares.  A gold setting is thought to enhance this property.  Pliny the Elder advises wearing peridot on the right arm for it to have the best effect.

Peridot is also thought by some to be effective for disorders of the liver, heart, lungs and spleen, and is used to promote a sense of calm and mental wellbeing.

Gemstone Detective

Be sure. Be smart. Buy with confidence