Hi Everyone,
I would like to continue our conversation with the next type of corundum species which is sapphire. I hope you will follow me and enjoy our journey through the fascinating world of sapphire. I like sapphire for the simple fact that it has many shades and colours to it. It is not what one would call a one hit wonder. I am especially fond of all the colours but I would have to say I am different in the fact that blue would be my least favourite colour of sapphire. I really would like to have one day a multicoloured sapphire bracelet. I find that all the colours together blend so harmoniously and look stunning all arranged to look like a rainbow on your wrist.
So let's talk sapphire. According to Walter Schumann in the book Gemstones of the World sapphires have the colour blue in various tones, colourless, pink, orange, yellow, green, purple and black. The sapphire has a Mohs hardness of 9 and the density is 3.95 to 4.03. The colour streak is white. There is no cleavage with sapphire which is the same as Ruby. The crystal system which was explained in the first part of corundum when we discussed the ruby is Trigonal, doubly pointy, barrel shaped, hexagonal pyramids, tabloid shaped. The composition is aluminum oxide. The transparency is transparent to opaque.
The name sapphire comes from the Greeks and means blue. The history of sapphire follows along the same lines as ruby in that in the book Gemstones of the World it is discussed that until 1800 sapphire used to apply to various stones. Even as far back as the Middle Ages sapphire was understood to mean what is now called lapis lazuli. In 1800 sapphire and ruby were recognized as corundum, and only at first was blue recognized as sapphire. Corundums of other colours were given special names which often were misleading. Some examples that were given in the book are Oriental peridot for the green sapphire and Oriental topaz for the yellow variety. Today all colours except red are called sapphire. The red of course being called ruby. Sapphires are qualified by the description of colour ie: green sapphire, pink sapphire. The colourless sapphire is called leuko-sapphire which is Greek for white. There is the rare pinkish orange sapphire called Padparadscha which is Sinhalese for "Lotus Flower". Mr. Schumann goes on to say, "There is no definite demarcation between ruby and sapphire. Light red, pink, or violet corundums are usually called sapphires, as in this way they have individual values in comparison with other colours. If they were grouped as rubies, they would be stones of inferior quality."
The blue sapphires colour agents are iron and titanium, vanadium in violet, a small amount of iron for yellow and green, chromium for pink and vanadium for orange. The most coveted colour of sapphire is the pure cornflower blue. Some of the more famous sapphires are the Star of India(536cts) which is considered to be the largest cut star sapphire, which is owned by the American Museum of Natural History in New York. There is the Midnight Star(116cts), which is a black star sapphire and the Star of Asia(330cts) which is owned by the Smithsonian Institution in Washington, D.C. Two other famous sapphires, the St.Edward's and the Stuart are part of the English Crown Jewels.
As one can see there is alot we can learn about sapphires. I hope everyone out there learned something interesting and fun today. I enjoyed learning about the sapphire and I found it interesting about the famous gems. Please drop me a line, let me know what you think. I enjoy hearing from everyone. Until next time.
The rare gem lady
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