Birthstones for March and April
In the second of the six-part series, ADORN focuses on birthstones associated with the months of March and April. Aquamarine, the birthstone for March, reflects the colour of the sea. Due to few inclusions, its clarity is often compared to that of water and is believed to symbolise the purity of spirit and soul.
Legend has it that sailors would wear the stone to protect themselves from unforeseen danger, guaranteeing a safe voyage. The calming effect of the stone was once associated with treating bouts of anxiety. Also known to be associated with keeping one youthful, the blue-green gemstone is a jewellery designer’s delight. Those born in April can take delight in the fact that their birthstone, the diamond, is one of the most sought-after gemstones in the world, almost making it a birthright to own at least one sparkling diamond.
Considered as the invincible gem, it is the hardest substance known to man and is virtually fire-proof. Due to these intrinsic properties, it is believed that diamonds can enhance a person’s level of clarity and balance, boosting endurance and make them strong.
Read on as the Gemological Institute of America (GIA), helps you understand more about these birthstones.
Aquamarine: The Blue Beauty
Did You Know?
Aquamarine is the green-blue to blue variety of the mineral beryl (the same mineral as emerald). The gemstone’s name is derived from two Latin words: aqua, meaning “water” and marina, meaning “of the sea.”
Aquamarine’s hardness and transparency make it popular with designers, artists and carvers. The gemstone’s crystals are known to be large in size and relatively clean and well- formed, making them particularly valuable to mineral specimen collectors.
Many large aquamarine crystals have been discovered in Brazil, the world’s most important source of gem-quality aquamarine. The largest on record, found in 1910 in Minas Gerais, Brazil, weighed 244 lbs (110 kg). Pakistan is another significant producer of aquamarine, while Australia, Kenya, Madagascar, Mozambique, Nigeria, the US and Zambia are less significant sources.
China recently became the world’s leading producer of small, commercial-quality aquamarine. It’s widely used in most of the mass-market jewellery available through home-shopping networks and other high-volume outlets. Aquamarines can be cut into almost any shape, but cutters often fashion them as emerald cuts or as round or oval brilliants. The rough is fairly plentiful, so well-cut stones are fairly common.
Aquamarine’s colour range is very narrow: it can be blue, very slightly greenish blue, greenish blue, very strongly greenish blue or green-blue. The gem’s most valuable colour is a dark blue to slightly greenish blue with moderately strong intensity.
The gem is pleochroic, which means it shows different colours in different crystal directions, and in the case of aquamarine, they’re near-colourless and strong blue. Fortunately, the blue pleochroic colour corresponds with the cutting orientation that retains the most weight, with the table facet aligned parallel to the length of the crystal.
The colour of untreated aquamarine is often strongly greenish, but heat treatment usually gives it a more bluish appearance. Nearly all the blue aquamarine found in jewellery is heat treated. The treatment is undetectable and the colour appears to be permanent. Because of widespread concern about treatments, untreated gems – like natural-colour aquamarine – appeal more than ever to informed consumers.
The most common aquamarine imitations are treated blue topaz, pale blue glass and synthetic blue spinel coloured by cobalt. Standard gemmological tests easily distinguish aquamarine from its imitators. Most faceted aquamarines are eye-clean. Stones with eye-visible inclusions are usually fashioned into cabochons, beads, or carvings.
How to Care for Aquamarine
Aquamarine is 7.5 to 8 on the Mohs scale of mineral hardness, so it is a durable gemstone for jewellery as long as it is treated with care. Heat exposure is not recommended for aquamarine, but the colour is stable against light exposure. Aquamarine can be attacked by hydrofluoric acid.
Warm soapy water is always a safe cleaning method for aquamarine. Cleaning by ultrasonic and steam cleaners is usually safe unless the stone has liquid inclusions or fractures. Rarely, aquamarine might be fracture filled. These stones should only be cleaned with warm soapy water.
Diamond: The World’s Most Popular Gem
Did You Know?
Most diamonds formed more than a billion years ago, under high temperature and pressure conditions that exist only within a specific depth range (about 100 miles) beneath the earth’s surface. The only gem made of a single element, diamond is typically about 99.95% carbon. The other 0.05% can include one or more trace elements that aren’t part of the diamond’s essential chemistry.
Diamonds have long been regarded as beautiful objects of desire. Historians estimate that India was trading in diamonds as early as the fourth century BC. Brazil emerged as an important source in the early 1700s and dominated the diamond market for more than 150 years. Explorers unearthed the first great South African diamond deposits in the late 1800s. World diamond mining expanded dramatically with the discovery of sources in Australia in 1985 and important new deposits in northern Canada in 2000.
The 4C’s: Clarity, Colour, Cut and Carat Weight
Diamonds come in many colours. Those ranging from colourless to light yellow and brown fall within the normal colour range. Within that range, colourless diamonds are the most valuable and set the standard for grading and pricing.
Clarity characteristics refer to diamond’s internal features, called inclusions, and surface irregularities, called blemishes. Clarity is the relative absence of inclusions and blemishes. Flawless diamonds are very rare and command top prices.
Cut refers to the proportions, symmetry and polish that effects how a diamond’s facets interact with light. Diamonds with different proportions and good polish make better use of the light, and will be bright, colourful and scintillating.
The term “cut” can also describe a fashioned diamond’s shape. Shapes other than the standard round brilliant are called fancy cuts. The best known are the marquise, princess, pear, oval, heart and emerald.
Diamond size is measured by weight in terms of metric carats. One carat is two-tenths (0.2) of a gram. Diamonds are weighed to a thousandth (0.001) of a carat and then rounded to the nearest hundredth, or point. Fractions of a carat can mean price differences of hundreds – even thousands – of dollars, depending on diamond quality.
Large diamonds are rarer than small diamonds. So although a 1-carat diamond weighs the same as four 0.25-carat diamonds, if all the other quality factors are equal, the larger diamond is worth much more than the sum of the four smaller diamonds.
Many diamonds emit a visible light called fluorescence when they’re exposed to ultraviolet (UV) radiation. Blue is the most common fluorescent colour in gem-quality diamonds. In rare instances, fluorescence can be white, yellow, orange or other colours. Strong blue fluorescence can make a light yellow diamond look closer to colourless in sunlight. If the fluorescence is too strong it can make the stone look cloudy or “oily,” which can lower the value of the diamond.
How to Care for diamonds
Diamonds are the hardest material on earth – 58 times harder than anything else in nature – but any stone, including a diamond, will break if it’s hit hard enough in the right place. Warm water and mild soap with a toothbrush is a safe way to clean diamond jewellery. Diamonds can also be safely cleaned with lint-free cloths and commercial jewellery cleaning solutions.