The Name: Ceylon

Ceylon was initially known as Ceilão, a name given to Sri Lanka by Portuguese colonisers in 1505. The British then re-colonised the land in 1798, transliterating Ceilão into English as Ceylon. Sapphires found in Ceylon were originally famous because of the vibrant medium blue hues, however, there is more to the opinion of the populace and the demand of the people.

Colours of Sapphire and Why?

Contrary to popular belief Ceylon Sapphires occur in many different colours, ranging from colourless to black. Also mentioned in the article on Madagascan Sapphires, red sapphires are characteristically known as rubies. Rubies are crystal forms of aluminium oxide, containing traces of chromium and iron impurities that absorb yellow-green light, thus deeper ruby red colours appear with increased content. Purple sapphires contain traces of hard, silver-grey malleable transitional metals that come in different shades. Colourless sapphires, commonly known as white sapphires in the gemstone markets, are stones of corundum that contain only 0.01% of titanium. Traces of iron can bring a very pale green colour. The impurities of iron and titanium combined perfectly together can express the deep-blue colour of royalty we commonly associate with sapphires today.

Blue Ceylon Sapphires

The Ceylonese Blue sapphire exists in various mixtures of secondary hues and the original blue. The evaluation of Blue Sapphires are based on the purity of their colour. The popular royal blue colour arises due to a concept called “inter-valence charge transfer”. It is a process that describes the creation of a magnificent colour with only the lowest percentage of impurities on the atomic level. Additionally, when the stone reflects a specific wavelength of light, and the impurities in the stone absorbs the other wavelengths, it shows a different colour. As a result, this absorption of light makes little particles called electrons jump into different shells, allowing the stone to express colour.

Pink Sapphires

Sapphires of any colour apart from blue are “fancy” sapphires and range in a variety of colours: yellow, green, orange violet and many more. Similarly, pink sapphires are also a common commodity in the gemstone market. Appearing in light and dark pink depending on the quality of the chromium used, the pink sapphire is common in “halos” in jewellery. The distinction between a ruby and a pink sapphire depends on the amount of chromium within the stone. As a regulation, in the United States, there exists a minimum colour saturation which a ruby has to reach; if not, however, the stone is a pink sapphire.

Padparadscha Sapphires

“Padparadscha” is a name coming from the colour of the lotus flower. Literally, described as a light to medium toned, pink-orange corundum originally found in Sri Lanka, Vietnam and some parts of East Africa, its visual effect, takes away the breath of many, even Princess Eugenie. Her engagement ring features a magnificent Padparadscha sapphire, bringing the total value of the ring to approximately $130,000.

Star Sapphires

Star sapphires are sapphires that support a beautiful star, which dances on the stone. In other words, Asterism is the name of this phenomenon. The intersecting needle-like inclusions and the underlying crystal structure of the star sapphire cause the star-shaped appearance. The largest sapphire in the world is a blue star sapphire, mined in Sri Lanka called The Star of Adam.

Colour-Change Sapphire

Sapphires also feature a colour changing variety, which shows a unique property which causes the colour to change in different types of light. The aforementioned colour change is due to the interaction of light with the sapphire, which absorbs different wavelengths of light.

Sapphire Mining in Sri Lanka

Sapphire mining occurs on alluvial deposits, which are unconsolidated, loose and sediment soil that has been reshaped and eroded by water in a non-marine settling. Furthermore, alluvial deposits are contain particles like clay, silt and large particles of sand and gravel. They are mined from a wide variety of countries such as Sri Lanka, India, Kenya, Australia, Malawi, Thailand, Nigeria, Pakistan, the United States and many more.

Depending on the location characteristics of the sapphires also change. The Sapphires in Australia have a higher iron content, and are therefore darker and closer to green in colour. In contrast, the sapphires from Sri Lanka, have a unique property which has a dull fluorescence under ultraviolet light. Also, various microscopic inclusions would also differ depending on their origin.

Heat Treatment

Treatment in sapphires occurs in several methods: including heat treatment, where the sapphire undergoes heating in temperatures up to 1,800°C. Likewise, modern methods include heating the sapphire in a “nitrogen deficiency atmosphere oven” for one week or more. In addition, traditional methods of heating demonstrates a heat treater blowing air through a tube to maintain a a constant temperature. Moreover, the final conclusion to heat treating shows the stone losing all the silk and becoming crystal clear under magnification, with minor inclusions dissolving into the stone.

Interestingly, Ceylon sapphires which are not suitable for jewellery are used as an insulating substrate for semiconducting circuits.

Conclusion

In conclusion, sapphires come in a variety of colours and a variety of types which have their own characteristics. These characteristics either increasing the value of the stone in the market or making them increasingly rare. All in all, common natural gems like the sapphire, as mentioned above, are cut and polished to be worn as jewellery.

References:

Princess Eugenie's engagement ring 2018, photograph, News.com.au, viewed 5 May 2019, <https://cdn.newsapi.com.au/image/v1/824c76947255a23fd20f41b4ccdc6d57>.

Sri Lanka on a Map 2011, Illustration, Wikipedia, viewed 5 May 2019, <https://www.google.com/url?sa=i&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjh8f-PuoPiAhVafisKHaJnAQAQjRx6BAgBEAU&url=https%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3ASri_Lanka_in_the_world_(W3).svg&psig=AOvVaw1Psd9Fdvfwd3emiULoqb02&ust=1557113519730180>, Creative Commons license: <https://commons.wikimedia.org/wiki/File:Sri_Lanka_in_the_world_(W3).svg>.

The Star of Adam n.d., photograph, WorldKings, viewed 5 May 2019, <http://worldkings.org/Userfiles/Upload/images/the%20star%20of%20adam%20-1280x%20866.jpg>.