CHAPTER - 2

BLUE SAPPHIRE: A PROFILE

Some of the most beautiful and valuable precious stones like red Ruby and Sapphire come from the mineral family of corrundum. Transparent corrundum of any colour except red is generally known as Sapphire. The red corrundum is called Ruby while the yellow or white sapphires are known as ‘Pukharaj’ i.e. the ‘Oriental Topaz’. Sapphires of medium to dark blue colour (that of the neck of a peacock) which are of remarkable brilliance and are perfect and faultless are the most costly and historically famous varieties.

Bartholomew Angelicus (13 th century) very aptly wrote – “The Sapphire is a precious stone and is blue in colour, much like the sky in fair weather and clear, and is best among precious stones and most apt and suitable for the fingers of kings.”

VARIOUS NAMES

The Blue Sapphire has different names in the various languages, viz:

HINDI	Neelam
SANSKRIT	Indraneel, Neelmani, Mahaneel, Shani-ratna, Neelopal, Shaurie
BENGALI	Indraneel
ARABI, FARSI	Neelam, Yakoot, Kabood
ENGLISH	Sapphire
Similarly, there are different names of corrundum in various languages of the world:
HINDI	Kurundam or Kurund
SANSKRIT	Kuruvind
ENGLISH	Corrundum
FRENCH & SPENISH	Korinun
GERMANY	Korund

The word ‘Sapphire’ has been derived from the island ‘Sapphirine’ in the Arabian Sea and the meaning of this word in English language is ‘blue’, whereas the word Ruby comes from the Latin word ‘RUBAR’.

COLOUR

A good quality sapphire bears the velvety cornflower blue or the bright-navy satiny or the dark electric blue colour. The colour of sapphires displays a large variety of tones and shades. Every shade of blue colour is represented amongst sapphires. We have stones of Indigo-blue, Berlin-blue, smalt-blue, cornflower-blue, greyish-blue, and the greenish blue which is specially common. So long as the depth of its colour does not interfere with its transparency, the darker it is in colour the more highly it is priced.

The most admired tone of colour for a sapphire is an intense cornflower-blue. But, at the same time the colour of ‘Kashmir’ sapphires is also regarded to be one of the best. It resembles the beautiful hue of the peacock’s neck, hence it is also called ‘Mayur-Neelam’. Most important feature of the Kashmir-sapphire is that it does not change its colour in electric light, while sapphires from other places exhibit a navy blue colour before the electric light. 

The distribution and uniformity of blue colour in the sapphire is often very irregular. Sapphires may show small gradations in colour from deep blue to yellowish or colourless stones.

As has already been said, colourless or white sapphire is known as leuco-sapphire and those which have definite yellow colour are described as Oriental Topaz. Only the sapphires of a uniform blue colour are regarded as worthy gems.

The blue colour of sapphire disappears on heating, hence it is possible to transform a patchy or pale-coloured stone into a leuco-sapphire. The blue colour of the sapphire, when we look at the stone in a certain direction, appears more or less tinged with green.

The pure blue colour of a sapphire crystal is best displayed in the cut stone when the table of the piece is perpendicular to the optic axis and paralled to the basal planes of the crystal.

There are a few more blue stones, which in some cases may resemble the sapphire, and may be mistaken for, or passed off as sapphire. These are ‘cordierite’ (water sapphire), kyanite, blue tourmaline (Indicolite), blue topaz etc. All these stones, without exception, differ from the sapphire in density, hardness, refraction, reflection etc. The table given below will show the comparative physical properties of the above mentioned stones:

 

Sl. No	Gemstone	Specific  gravity	Hardness	Refractive		Double Dicharoism Reflection
				Index
				(W)	(E)

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1.	Blue Sapphire	3.99	9.0	1.76 - 1.77	0.008	Strong
2.	Benitoyat	3.67	6.5	1.75 - 1.00	0.047	Strong
3.	Kyanite	3.67	4.6	1.71 - 1.73	0.718	Strong
4.	Spinel	3.60	8.0	1.72 - Nil	Nil
5.	Indicolite (Tourmaline)	3.10	7.2	1.62 - 1.64	0.020	Strong

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SCIENTIFIC ANALYSIS

CHEMICAL COMPOSITION

The chemical composition of a beautiful transparent Blue-Sapphire is as given below:

- Alumina (Al 2 O 2 )                         97.51
(Aluminium and Oxygen)

- Iron-oxide (Fe 2 O 2 )                       1.89

- Silica (Si O 2 )                                    0.80

TOTAL                                              100.20

(A slight mixture of cobalt gives it the blue colour)

CRYSTALLING FORM

The form of a crystal of sapphire prism and rhombohedron are generally not well developed but the hexagonal bipyramid is always present.

Some of the good quality sapphire crystals bear on their basal planes a six-rayed star of chatoyant light. This appearance, which is known as ‘asterism’ is often very beautiful, and is best displayed by cutting the crystal. These are known as ‘Star-sapphires’.

PHYSICAL CHARACTERS

(a)	Specific gravity	3.97 to 4.08 (very high)
(b)	Cleavage	Cleavable, having two cleavages, one paralled to one or more faces of the primitive rhombohedron and the other paralled to the basal plane.
(c)	Hardness	9. 0 (next to Diamond which is the hardest of all the gemstones).
(d)	Optical characters
	1 Transparency	Noble and precious varieties are transparent in appearance
	2 Lustre	Very fine, brilliant and perfect. Owing to its great hardness, the lustre is retained even after rough usage and hard wear.
	3 Refraction of light	High index of refraction. Though its refraction is strong, it is considerably less than that of a diamond.
	4 Double refraction of light	Its double refraction is  small. It shows no marked flashes of prismatic colours as does the diamond.
	5 Dichroism	Strong
	6 Special optical appearances and colour effects	When the li ght is passed through a crystal of sapphire in the direction of  its optic axis and seen in a dichroscope, the two images formed will be either pure blue or blue tinged with violet. The colour will remain unchanged, even when the stone or the instrument is rotated.
(e)	Effects of temperature, electricity etc.	If the crystal of sapphire is  exposed to very high  temperatures, its colour disappears and it becomes grey and cloudy. Such decolouration does not take place in cases of other stones. The Kashmir-sapphire does not change its colour in electric light, while those from other places exhibit a navy-blue colour when put before the electric light.

 

VALUE

A flawless sapphire of perfect transparency, velvety lustre, and of a uniform deep corn-flower blue colour can fetch equal value to that of a diamond of good quality and of the same weight, but it can never command higher price than that of a ruby of the same description. Indeed, the prices of sapphires are almost proportional to their weight.

OTHER GOOD QUALITIES

The good qualities of an auspicious Sapphire have been enumerated in one of the Sanskrit ‘Shlokas’ as under:.The Gem which 

– bears one uniform blue colour and reflects no colour other than its own

– is of a high specific gravity

– has brilliance or radiance

– is absolutely clear, pure and perfectly transparent

– is a solid compact crystal and appears to be a single and complete unit in itself

– is lovely and smooth (soft in touch)

– shows asterism, that is, it exhibits a star like effect from the interior when viewed in reflected light and spreads out rays from inside is an excellent sapphire.

LIMITATIONS AND FLAWS

Sapphires bearing all the above mentioned good qualities are rare and very costly. The degree of excess and deficiency of good qualities and flaws determine the higher and lower class of a gem. Some of the flaws, which may be found in a sapphire have been given below:

1. Greenish and milky shade

2. Some capillary (thread like inclusions) in the body

3. May be silky

4. Fissures in its structure

5. Reflecting colours other than its own

6. Bearing some hole or cavity in its body

7. Displaying a window in its texture

8. Opaque or dull or shaded lacking luminescence

QUALITIES AND DEFECTS OF THE SAPPHIRE

The qualities and defects of the Sapphire are being reproduced here from ‘MANI-MALA’ or ‘A Treatise on Gems’ (1897), a much sought after book authored by S. M. Tagore (INDIA) :

403. As Rubies are good, middling and bad, – so it is also with Sapphires.

406-407. Of gems, those which are blue, are Sapphires; those which are red, are Rubies; those which are green, are Emeralds; those which are red with a shade of yellow are Kasayas; those which are ash-colored with a yellow shade, are Pushparagas; those of the last which are red, are called Kaurandakas.

408. Weight, coolness, depth of color, the quality of being Parsvavarti and beauty, invest a Sapphire with matchless worth.

409. That Sapphire which combines great weight with small bulk is called Guru : such a gem conduces to increase of family. That which always gives out moisture is called Snigdha. A Snigdha Sapphire brings on accession of wealth.

410. That Sapphire which, on being exposed to the morning sun, flames in a blue effulgence, is termed Varnadhya. It brings prosperity..411. That Sapphire through which any lustrous substance such as crystal, silver, gold, is seen, is entitled Parsvavarti. A Parsvavarti Sapphire brings on fame.

412. That Sapphire which, when placed in a pot, darkens it all through, is called Ranjaka. This gem increases wealth and is conducive to fame and increase of family.

413. Avraka, Trasa, C’itraka, Mridgarva, Asmagarva and Raukshya are the six defects of Sapphires.

414. A Sapphire the surface of which wears a mica-like sheen, goes by the name of Avraka. Such a gem brings about loss of wealth and life.

415. That mark in a Sapphire which at first sight looks like a rift, is called Trasa. A Trasa renders one liable to bites. That Sapphire which is party-colored, is called C’itraka : it causes loss of family dignity.

416. The Sapphire which contains dirt, has the sobriquet of Mridgarva. This gem produces a variety of skin-diseases like itching.

417. That which contains gritty fragments, is called Asmagarva. This defect is destructive. That which is rough, is called Raukshya. Banishment is the consequence of wearing this jewel.

418. A flawless, sterling Sapphire brings its wearer strength, fame and length of days.

419. The man who wears a Sapphire of spotless chastity, finds favor with Narayana (The Preserver the Hindu Triad) and acquires longivity, family dignity, fame, understanding and wealth.

CHIEF LOCALITIES

The mode of occurrence of the sapphire is practically the same as that of ruby. It is found in sands and in solid rock, frequently with ruby. There is probably no single locality where one stone is found without the other. Sapphire is the more abundant of the two in Siam (Thailand), in Ceylon (Sri Lanka), at Zanskar in Kashmir, in gold and diamond sands of Australia, specially of New South Wales, and in Montana in the United States. Other localities, such as the European ones are unimportant. Here, a short description of some of the chief localities is being given:

1. SIAM (Thailand)

The stones found is Siam are not only in the largest quantity but are also of the finest quality. It is estimated that 60 % of the world’s sapphire production is yielded by the Bo-Pie-Rin mines in Battambang of Thailand. Stones found there are of very fine quality, having intense blue colour and velvety luster. These are quite hard and tough, yet smooth like silk. However, star-sapphires are not found in Siam.

2. BURMA (Myanmar)

Fine star-sapphires of fine colour are found in the mines of Burma. Large sized crystals are frequently available here. The largest faultless stone yet found there weighs 79.5 carats. However, discovery of stones weighing 1988, 951, 820 and 253 carats has also been recorded. The colour of Burmese sapphires has a very little greenish tinge and is usually very dark.

3. CEYLON (Sri Lanka)

Sapphire is also produced in Ceylon with many other precious stones, namely – ruby, topaz, amethyst, cat’s eyes, quartz, zircon, tourmaline, moon-stone etc. On the south coast of this island Saffragam district is rich in sapphires where a considerable number of large sized and fine quality stones are found. Though not of good quality the sapphires of Ceylon fetch high price. Their colour is also less attractive. Though their blue colour has got a mixture of reddish tinge, they do not possess such powerful rediant colour spot as is seen in the Kashmir sapphires.

4. INDIA

   A. Kashmir:

Since 1881, sapphires have been mined in large quantity in the Zanskar mines of Kashmir in India. Mr. T.H.D. La Touche of the Indian Geological Survey was the first person who succeeded in visiting this locality situated at an altitude of 11,000 feet in the north-west Himalayas. The fine blue coloured crystals were found there in abundance. At that time, the innocent natives of the locality collected them like potatoes and sold them to the merchants of Shimla and Delhi.

The crystals of Kashmir sapphires are well developed and are sometimes very large, measuring 5 inches in length and 3 inches in thickness, weighing 100 to 300 carats. They are often bluish-white or bluish-grey but specimens of a finer and richer blue colour of the peacock’s neck are also frequently found, which form an exclusive class of their own. It may, however be added that majority of the stones found here possess, wholly or in part, a milky cloudiness or a silky luster. Some of them suffer from flaws and blemishes and often have window hole or cavity in their texture.

   B. Salem (Tamilnadu):s

A new mine has been discovered here. The product of this mine displays a fusion of yellow and blue colours like those of Bangkok mines in Thailand, but at the same time they have got a deeper greenish tinge.

5 AUSTRALIA

The mineral is found in gold-sands with diamond in Victoria, South Australia, Queensland, and especially in New South Wales. Australian sapphires, as a rule, are too dark and often vary from perfect transparency and absence of colour through various shades of blue and grey to almost absolute opacity and dark blue colour. They posses little shine and sometimes vary in hardness also.

6. UNITED STATES

All varieties of precious corrundum – ruby, sapphire, oriental topaz, oriental emerald etc. are found in the western portions of North Carolina and South Carolina, which extend into Georgia and Alabama. The other region which is specially rich in sapphire and other coloured varieties of corrundum is in the State of Montana. The stones found in these regions are not of good quality. They have well developed crystals suitable for cutting. The colour of  these stones is also not fine, i.e. it is almost always pale in shade showing a variety of all possible intermediate colours.

7. COMBODIA AND OTHR COUNTRIES

Combodian sapphires are of a very beautiful and lovely colour.

Apart from the localities mentioned above deposits of sapphire are also found in Russia (near Troitsk Minsk), Ural mountains and Rhodhesia in South Africa, but their quality is very inferior and they are not much popular.

COUNTERFEITING

The blue stones which may be mistaken for, or passed off as sapphire have already been enumerated under sub-head COLOUR. The colour of sapphire is easily imitated in glass by adding to the strass a little cobalt oxide. Sapphire, diamond, colourless spinel, zircon, topaz, rock-crystal, and phenakite, as well as colourless strass, may each be mistaken for the other.

Of these, sapphires, zircon and spinel sink slowly in the heaviest  liquid (sp. gr. = 3.6), while all the rest float. Only diamond is capable of scratching leuco-sapphire, while this itself can scratch all the others. Glass, diamond, and spinel are singly refracting, and can thus be distinguished from the other stones mentioned above. Hence, it is not a matter of great difficulty to distinguish a colourless sapphire from the colourless stones it somewhat resembles.