Zircon assignment
- 1. The University of Azad Jammu & Kashmir The Institute of Geology TOPIC STUDY OF ZIRCON GROUP # 04 SUBMITTED BY SYED RASIB ALI ROLL # 26 SUBMITTED TO SIR SHAHAB PERVAIZ
- 2. OUTLINE:. Introduction Physical properties Optical properties Varieties Occurrence Zircon sources Uses similar gemstone gems market in pak Mining in pak Gallery References
- 3. Zircon:. Zircon is a mineral belonging to the group of Silicates, Nesosilicates. Its chemical name is zirconium silicate and its corresponding chemical formula is ZrSiO4. While zircon in fashioned form can be found in a wide range of colours the crystals are usually reddish brown and heat treatment is needed to produce the colourless, golden yellow and bright blue colours most seen in jewellery. Other colours, often very pleasing, might be called fancy zircons as the range is considerable. . Other colours, often very pleasing, might be called fancy zircons as the range is considerable. We should understand from the first that some zircons are much older than others and, like older people. Properties of zircon:. Cleavage: Indistinct Color: Brown, Reddish brown, Colorless, Gray, Green. Density: 4.6 - 4.7, Average = 4.65 Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern. Luster: Adamantine Streak: white Hardness: 7.5 – Garnet System: Tetragonal Tenacity: Brittle Transparency Transparent to opaque Specific Gravity 4.6 - 4.8 Optical Data of Zircon:. Type: Uniaxial (+) Surface Relief: Very High Dispersion: Very strong Pleochroism: Weak
- 4. Varieties 0f Zircon:. Jacinth: Yellow, orange, brown, or red variety of Zircon. Also synonymous with Hyacinth. Though the terms Jacinth and Hyacinth are no longer used in the gem trade, they are historically important names going back to biblical times. In ancient times, before there were mineralogical classifications for gemstones, the term Hyacinth may also have referred to an orange or brownish Topaz. Jargon: Colorless, pale gray, or pale yellow variety of Zircon. Matura Diamond: Trade name for colorless Zircon. Starlite: Blue gem variety of Zircon. The color of Starlite is rarely natural, and is almost always heat treated. Occurrence:. Zircon, zirconium orthosilicate, is found in most igneous rocks and some metamorphic rocks as small crystals or grains, mostly widely distributed and rarely more than 1% of the total mass of the rock. It is also found as alluvial grains in some sedimentary rocks due to its high hardness. Zircon has a high refraction index and, when the crystals are large enough, is often used as a gemstone. In geology, zircon is used for radiometric dating of zircon-bearing rocks (using isotopes of U which is often present as an impurity element, as is Th, radiogenic Pb, Hf, Y, P, and others). Zircon is a common accessory to trace mineral constituent of most granite and felsic igneous rocks. Zircon is rare within mafic rocks and very rare within ultramafic rocks
- 5. Due to its hardness, durability and chemical inertness, zircon persists in sedimentary deposits and is a common constituent of most sands. Zircon Sources:. Zircon sources include Cambodia, Burma (Myanmar), Sri Lanka (Ceylon), Australia, Tanzania, Mozambique, Madagascar, Nigeria, Pakistan, and Afghanistan. Uses:. Zircon is an important gemstone, with several color forms used in various forms of jewelry. Zircon is also the most significant ore of the element zirconium, and it is also the most important ore of the rare element hafnium, which can be present in considerable quantities in Zircon. In several localities, Zircon is also an ore of the radioactive element thorium. Zircon of all colors are used as gems, but blue, golden-brown, and white are the colors most often used. Blue Zircon, the most popular color, has a lively pastel blue, and occasionally has a very desirable striking bright blue color. Colorless Zircon is usually cut with a brilliant cut to bring out its fire to its fullest capability. It is often used as a cheaper, yet natural alternative to Diamond. The other color forms (yellow, green, pink, and purple) are less often seen in jewelry. Zircon is the traditional birthstone for December. Production chart of worldwide of zircon.
- 6. Similargemstones:. Because Zircon occurs in so many colors, there are many gemstones that resemble it. Colorless Zircon resembles Diamond. It also resembles synthetic Diamond simulants such as Cubic Zirconia and Strontium Titanate. It is distinguished from these and other colorless gem forms by its strong double refraction. Blue Zircon can be similar to Aquamarine, Blue Topaz, Blue Tourmaline, and Blue Spinel; Golden-brown Zircon can be similar to Topaz, Citrine, and Sapphire; Yellow zircon can be similar to Yellow Diamond, Yellow Sapphire, Golden Beryl, Chrysoberyl, and Topaz; and Pink Zircon can be similar to Rose Quartz, Morganite, Kunzite, Spinel, and Pink Topaz. The luster, fire, and double refraction make Zircon gemstones distinguishable from most others. Gem markets:. The southern port city of Karachi was once the biggest market of facet and rough cut gems in Pakistan. However, after the Soviet invasion of Afghanistan, the significance of Karachi was reduced and Peshawar became the hub of gemstones trade. Due to the long and porous border with Afghanistan, many gemstones from the country are now also found in Pakistan and since 1979, Peshawar is the only direct market for all gems found both in Pakistan and Afghanistan. Pakistan Gems and Jewellery Development Company regularly holds Gem Bazaars (exhibitions) in Quetta and Peshawar where gemstones attested by Gemstone Identification Laboratory are traded. In Islamabad, so far three such exhibitions have been held. In January 2012 exhibition, around two hundred companies from Pakistan displayed their items. The third Islamabad Gem Exhibition was held in February 2013 where 80 national gem traders displayed their products. Mining areas in Pak of Zircon:. Pakistan has large reserves of mineral ores and gemstones. Pakistani gemstones include a variety of minerals such as peridot, ruby, aquamarine, topaz, ruby and emerald, making the country significant in the mineral world.
- 7. In Gilgit Baltistan mining area is Chillas. Baluchistan mining area is chagai. Also the Sindh and tribal areas of Pak zircon is reported Gallery:.