Famous Sapphire and Possibilities for Confusion

Large sapphires are rare. They are sometime named in the same way as famous diamonds. The American Museum of Natural History ( New York) owns the "Star of India" perhaps the largest cut star sapphire (536ct); also the "Midnight Star" a black star sapphire (116ct). The "Star of Asia" a star sapphire weighing 330ct, is owned by the Smithsonian Institution in Washington D.C.
Two famous sapphires (St. Edward's and the Stuart sapphire) are part of the Lincoln, and Eisenhower have been carved out of three large sapphire, each weighing roughly 2000ct.

Sapphire can be confused with various stones. The blue sapphire looks similar to benitoite, indicolite, iolite, kyanite, spinel, tanzanite, topaz, and zircon, as well as blue glass.
Some imitation are made from doublets-blue cobalt glass with a crown of garnet or crown of green sapphire and a pavilion of synthetic blue sapphire. Lately, doublets have appeared using two small natural sapphire. Star sapphire is imitated by using star rose quartz with blue enamel on a flat back; alternatively the star is engraved on the flat back of a synthetic cabochon or on glass.
Synthetic sapphire was produced with properties identical to the natural stone at the beginning of this century. Since 1947 synthetic star sapphire of gem quality have been sold.

December Gemstones

December-Turquoise, blue topaz and tanzanite represent a happy life that is filled with good fortune. Headaches may be relieved or prevented. Ancient practitioners believed that turquoise would actually change color when the wearer was ill or in danger.

The history of Turquoise.

What exactly are Turquoise? The word Turquoise is derived from the Greek word "Turkois" meaning "Turkish" because it was first brought from Turkey. Turquoise is formed over millions of years by a chemical reaction that occurs when water leaks through rocks which contain specific minerals such as copper and aluminium. The percentage of the minerals in the rock dictate the shade of the turquoise.

Turquoise meaning.

 Is regarded as a love charm. It is also a symbol of good fortune and success, and it is believed to relax the mind and to protect its wearer from harm. Turquoise rings, in particular, are thought to keep away evil spirits.

The history of Blue Topaz.

The word “topaz” is believed to derive from the Sanskrit word “tapas,” which can mean fire, heat, and passion. Others believe “topaz” comes from the Greek word “topazos,” which means “to search.” In 1969, Texas named blue topaz as its official state gem after miners discovered a small deposit of natural blue topaz underground.

Blue Topaz meaning.

Of all the precious stones in the world, blue topaz is the perfect fit for intellectuals. Writers, artists, and scholars give blue topaz meaning by wearing it because it is indeed made for them, promoting higher thinking and cognition. Other feelings attached to blue topaz are serenity, friendship, fidelity, integrity, and gentleness. Just looking into its calm, cool shade of sparkling blue can make you breathe a sigh of relief.

The history of Tanzanite.

Tanzanite is the blue/violet variety of the mineral zoisite (a calcium aluminium hydroxyl Sorosilicate) belonging to the epidote group. It was discovered in the Mererani Hills of Manyara Region in Northern Tanzania in 1967, near the city of Arusha and Mount Kilimanjaro. Tanzanite is used as a gemstone, and naturally formed tanzanite is extremely rare, still found only in the Mererani Hills.

Tanzanite meaning.

Tanzanite is called a "stone of magic" that helps with spiritual awareness and psychic insight. It is also sometimes called the "workaholic's stone".  This is because it helps you slow down and take it easy. This in turn, brings success in more areas of life. It relieves stress and depression, and enhances composure, poise, and harmony. Tanzanite is also said to transmute negativity. Physically it is said in healing folklore and crystal healing to be beneficial for stress related illnesses and high blood pressure in particular.  Note that healing crystal meanings are spiritual supports to healing and are not prescriptions or healthcare information. Tanzanite is related primarily to the throat and third eye chakras.

Deposits of Sapphire

Host rock of sapphire are dolomotized lime stones, marble, basalt, or pegmatite. It is mined mainly from alluvial deposits or deposits formed by weathering, rarely from the primary rock. Production methods are usually very simple. The underground gem-bearing layer is worked from hand -dug holes and trenches. The separation of clay, sand, and gravel is done by washing out the gemstones due to their higher density. Final selection is made by hand. Sapphire is much more common than ruby, as the substances which lend color to sapphire are more in Australia, Myanmar, Sri Langka, and Thailand.
Australia deposits have been known since 1870. The host rock is basalt; the sapphire are washed our of the weathered debris. Quality is modest. Under artificial light, the deep blue stones appear inky, blue green, nearly black; lighter qualities have a green tint. In recent decade black star sapphires have been found in Queensland. Accompanying minerals are pyrope, quartz, topaz, tourmaline, and zircon. Since 1918 good blue qualities have been found in New South Wales.
The alluvial deposits in upper Myanmar near Mogok are partially worked with modern methods and yield rubies and spinels as well as sapphires. The host rock is pegmatite. In 1966 the largest star sapphire was found here, a crystal of 63,000 ct (281l/12.6kg ).

Sapphire have been found in Sri Langka since antiquity. The deposits are in the southwest of the island in the region of Ratnapura. The mother rock is dolomotize limestone, which is enclosed in granite gneiss. There are also 10-20-in (30-60 cm) thick river gravel placers ( called illam locally) that are exploited from a depth of 3-33 ft ( 1-10 m). Sapphires are usually light blue, with a tinge of violet. There are also yellow and orange ( Padparadscha ) varieties as well as green, pink, brown, and nearly colorless stones. also star sapphire. Accompanying minerals are apatite, epidote, garnet, quartz, ruby, spinel, topaz, tourmaline, and zircon.

There are two sapphire deposits in Thailand: one in the region of Chantaburi, southeast of Bangkok, the other one near Kanchantaburi, northwest of Bangkok. The host rock is marble and/or basalt; placers and deposits formed by weathering are mined. The stone are of good quality in various colors, including star sapphire. Blue sapphire have a deep color, but tend to have a tings of blue-green.

The most desired sapphire used to come from Kashmir ( India), where the deposits were situated at a height of 16,500 ft (500 m) in the Zaskar mountains. 

Production varied since 1880, and the deposits have apparently been worked out. The host rock is kaolin-rich pegmatite in crystalline schist. The decomposition product yields sapphire of deep cornflower-blue color, often with a silky sheen. Most stones sold today as Kashmir sapphire come from Myanmar.

In the late 1800s sapphire deposits were discovered in Montana( United State). The host rock is andesite dikes. Mining is carried out on the dike rock, also from weathered material. Color of sapphire varies and is often pale blue or steel-blue. Mining has been interrupted repeatedly since the end of the 1920s,  but has been steadier in recent years.

There are also significant sapphire deposit in Brazil, Cambodia, China, Kenya, Madagascar, Malawi, Nigeria, Pakistan, Rwanda, Tanzania, Vietnam, and Zimbabwe. Isolated star sapphire have found in Finland.

Sapphire

The name sapphire ( Greek-blue) used to be applied to various stones. In antiquity and as late as the Middle Ages, the name sapphire was understood to mean what is today described as lapis lazuli. Around 1800 it was recognized that sapphire and ruby are gem varieties of corundum. At first only the blue variety was call sapphire, and corundum of other colors ( with the exception of red) were given special, misleading names, such as "Oriental peridot" for the green variety and "Original topaz" for yellow type.

Today corundum of gemstone quality of colors except red are called sapphire. Red varieties are called rubies are call rubies. The various colorless sapphire qualified by description, e.g., green sapphire or yellow sapphire . Colorless sapphire is called leuko-sapphire ( Greek-white), pinkish orange sapphire Padparadsha (Sinhalese for ''Lotus Flower'').

There is no definite demarcation between ruby and sapphire. Light red, pink, or violet corundum are usually called sapphire, as in this way they have individual values in comparison with other colors. If they were grouped as rubies, they would be stones of inferior quality. The coloring agents in blue sapphire are iron and titanium; and in violet stones, vanadium. A small iron content results in yellow and green tones; chromium produces pink, iron, and vanadium orange tones. The most desired color is a pure cornflower-blue. In artificial incandescent light, some sapphires can appear to be ink-color or black -blue.

Through heat treatment at temperatures of about 3100-3300 degree F (1700-1800 degree C), some cloudy sapphire, non distinct in color, can change to a bright blue permanent color.
Hardness is the same as ruby and also differs clearly in different directions ( an important factor in cutting). There is no fluorescence for all sapphires.
Inclusion of rutile needles result in a silky shine; oriented, i.e., aligned, needles cause a six-ray star sapphire .

Famous Rubies

Ruby is one of the most expensive gems, large rubies being rarer than comparable diamonds. The largest cuttable ruby weighted 400ct; it was found in Burma and divided into three parts. Famous stones of exceptional beauty are the Ewardes ruby (167ct) in the British Museum of Natural History in London, the Rosser Reeves star ruby (138ct) in the Smithsonian Institution in Washinton, D.C., the De Long star (100ct) in the American Museum of Natural History in New York, and the Peace ruby (43ct), thus called because it was found in 1919 at the end of World War I.
Many rubies comprise important parts of royal insignia and other famous jewelry. The Bohemian St. Wenzel's crown (Prague), for instance, holds a non faceted ruby of about 250ct. But some gems , thought to be rubies, have been revealed as spiniels, such as the ''Black Princes's ruby'' in the English State Crown and the ''Timur Ruby'' in a necklace among the English crown jewels. The drop- shaped spinels in the crown of the Wittelsbachs dating from 1830 were also originally thought to be rubies.

                                                                    Black Princes's ruby
Today rubies were cut in the countries where they were found. Because the cutters usually aim for maximum weight, the proportions are not always satisfactory, so that many stones have to be recut by dealers in other countries. Transparent qualities are cut in step and brilliant cut; less transparent stones, en cabochon or they are formed to carving. Only synthetic rubies are used for watches and bearings, formerly the most important technical application for natural stones.
Possibility for confusion with almadite, pyrope, spinel, topaz, tourmaline, and zircon. Since the beginning of the 20th century, there have been synthetic rubies with gemstone quality; these resemble natural ones especially in their chemical, physical, and optical properties. But most of them can be recognized by their inclusions as well as by the fact that they. in contrast to natural rubies, transmit shortwave ultraviolet light.
Numerous imitations currently are on the market, especially glass imitations and doublets. These have a garnet crown and glass underneath. There are many false names in the trade such as Balas ruby (=spinel), Cape ruby (=pyrope), and Siberian ruby (= tourmaline).

Deposit of Ruby

The host rocks of ruby are metamorphic dolomite marbles, gneiss, and amphibolite. The yield of rubies from such primary deposits is not economically profitable. Rather, secondary alluvial deposits are worked. Because of its high density, ruby is normally separated through the washing of river gravels, sands, and soil, then concentrate, and finally picked out by hand.
Production methods are still as primitive as they were a hundred years ago in many location. In state-owned mines, on the other hand, the usage of machinery is not exactly the rule, but much more frequent than in private companies. Some state regulated companies (e-g., Mogok in Myanmar) lately even work with highly mechanized machinery both above-and underground.
                                     
                                                            Mogok in Myanmar

                                                                   Rubies from Burma

Some of the most important deposits are in Myanmar, Thailand, Sri Lanka, and Tanzania. For centuries, the most important have been in upper Myanmar near Mogok. The ruby-bearing layer runs several yards under the surface. Apparently pigeon's blood color. They are consider to be the most valuable rubies of all. Large stones are rare. Mineral found together with ruby, often also of gemstone quality, are precious beryl, chrysoberyl, garnet, moonstone, sapphire, spinel, topaz, tourmaline, and zircon. In the early 1990s large new deposits were discovered at Mong Hsu in Myanmar. Rubies from Thailand often have a brown or violet tint to them.They are found southeast of Bangkok in the district of Chantaburi in clayey gravels. Shafts are sunk to a depth of 20 ft (8 m). However, in recent years Thai ruby production has been declining.
In Sri Lanka deposits are situated in the southwest of the island in the district of Ratnapura. Rubies from these deposits( called illam by the local population) are usually light red to raspberry-red. Some of the rubies are recovered from the river sands and gravels.
Since the 1950s Tanzania has produced a decorative green rock, a zoisite(anyolite), with the most opaque rubies. Only a few crystals are cuttable, most being used as decorative stones. On the upper Umba River(northwest Tanzania), on the other hand, rubies with gemstone quality have been found that are violet to brown-red.
Other mining deposits are in Afghanistan, Australia (Queensland, New South Wale), Brazil, Indian, Cambodia, Kenya, Madagascar, Malawi, Nepal, Pakistan, Zimbabwe, Tajikistan, the Unite States ( Montana, North Carolina), and Vietnam.
Small ruby deposits can also be found in Switzerland (Tessin), in Norway, and the southwest Coast of Greenland.

                                                        Ruby's deposit in Cambodia

 

Ruby

Ruby is thus named because of its res color(Latin-ruber). It was not until about 1800 that ruby, as well as sapphire, was recognized as belonging to the corundum species. Before that date, red spinel and the red garnet were also designated as ruby.
The red color varies within each individual deposit, so it is not possible to determine the source area from the color. The designations ''Burma ruby'' and ''Siam ruby'' are therefore strictly erroneous, and refer more to quality that origin. The most desirable color is the so-called ''pigeon's blood,'' pure red with a hint of blue.
The distribution of color is often uneven, in stripes or spots. The substance that provides thee color is chromium, and in the case of brownish tones, iron is present as well. As a rough stone, ruby appears dull and greasy, but, when cut, the luster can approach that of diamond. Heat treatment is commonly used to improve the color.
Ruby is the hardest mineral after diamond. However, the hardness varies in different directions. Ruby has no cleavage, but has certain preferred directions of parting. Because of brittleness, care must be taken when cutting and setting.
Inclusion are common. They are not always indicative of lower quality, but show the different between a natural and a synthetic stone. The type of inclusion (minerals, growth structures, canals, or other cavities) often indicates the source area.
Included rutile needle bring about either soft sheen (call silk) or, when cut en cabochon , the rare cat's eye effect, or more often the very desirable asterism-a six -rayed star, which shimmers over the surface of the stone when it is moved. Nowadays there are also Trapiche Rubies on the market. Their appearance is equal to the Trapiche Emeralds.

        Natural Ruby from Cambodia