EDUCATION
PINK SAPPHIRE FULL GUIDE
CHARACTERISTICS OF PINK SAPPHIRE
Etymology: from the Ancient Greek sappheiros, meaning blue stone. However, sapphires can be found in many colors, including pink.
Family: Corundum
Chemical composition: Aluminum Oxide – Chromium
Hardness: 9 on the Mohs scale
Density: 3.9 – 4.05
Optical property: Uniaxial birefringent
Refractive index: 1.75 – 1.77
Birefringence: 0.008 – 0.009
Crystal system: Trigonal
THE ORIGIN OF PINK SAPPHIRE
Pink sapphires are found mainly in Sri Lanka, also known as Gem Island (Ratna Dweepa in Sanskrit). But beautiful pink sapphire can also be found in Myanmar, East Africa (Tanzania and Kenya) and Madagascar, where mines were discovered in the south-west of the island in the early 1990s.
Some of the most notable sources include:
- Sri Lanka
- Kashmir
- Thailand
- Madagascar
- Montana
- Australia
- Burma
CARAT
Gemologists use a unit called a carat to indicate the weight of gemstones. The more a stone weighs in carats, the more valuable it is. As a point of reference, a 1-carat pink sapphire weighs 0.2 grams, so a sapphire weighing 1 gram is a 5-carat gemstone. But be careful not to confuse carats with karats, which is a unit used to determine the purity of precious metals.
THE COLOR OF PINK SAPPHIRE
Pink sapphires come in a variety of unique colors which are created by varying quantities of chromium inside each individual stone. These different hues of color range from pale pink – known as 'baby pink' – and ‘bubble-gum’ pink to a dark, slightly purplish-red pink, with saturation levels varying from light to intense. The most sought-after colors are pure pink and highly saturated, but color preferences are, of course, highly subjective.
HUE
The hue of a gemstone describes its shade. Pink sapphires have many different hue combinations that make each stone completely unique.
SATURATION
Saturation refers to the degree of color intensity of a gemstone. This is an essential indicator in the valuation of pink sapphire.
TONE
pink sapphires tend to have a medium to medium-dark tone.
THE CLARITY OF PINK SAPPHIRE
Pink sapphire has slight impurities, also known as inclusions, which look different depending on the origin of the gemstone. They may be internal or superficial inclusions, such as black spots or microscopic feathers. These impurities can also help identify the origin of a gemstone.
Interestingly, the clarity of pink sapphire is assessed by the naked eye, rather than through a 10X magnifying glass like diamonds are.
CUTS & SHAPES
The pink sapphire is a solid stone that can be cut into different shapes (cushion, pear, oval, heart, rectangle, round, etc.).
Pink sapphire is also a dichroic stone, which means that its color changes depending on the angle from which it is looked at. This is why it is generally advised to keep within certain proportions (table plane perpendicular to main C-axis) during cutting in order to bring out the best hue possible. Lapidaries also tend to stay close to the pink sapphire's original shape so as not to lose too much of the raw material. More often than not, the rough crystal takes a hexagonal pyramid shape. This is why sapphires are often deep stones. The depth of the stone also keeps the color of the pink sapphire perfectly intact.
OVAL PINK SAPPHIRE
ROUND PINK SAPPHIRE
PEAR PINK SAPPHIRE
CALENDAR
The pink sapphire is the birthstone of anyone born in the month of September. It is also used to celebrate 16 years of marriage in France and 45 years of marriage in the US (sapphire wedding anniversary).
TREATMENT
Experts employ a variety of methods to remove impurities from untreated pink sapphire and ensure maximum radiance. These are known as either enhancements or treatments.
The most common method is an enhancement that consists of heating the stone in an oven so that its inclusions crystallize and become less visible. As such, most pink sapphire from Madagascar undergoes this 'moderate' heat treatment, where the stone is exposed to a temperature of 400° for a few minutes only. This enhancement also tones down purple shades in the pink sapphire, giving it a beautiful pink hue.
However, it should be noted that certain oil- or resin-based treatments which change the shape of the stone are prohibited in the industry.