Turquoise Gold Jewellery Katak Plain Erring.

Turquoise Gold Jewellery Katak Plain Erring.

By Stone.

Bisbee turquoise commonly has a hard chocolate brown coloured matrix.

Untreated turquoise, Nevada, US. 

Turquoise Ruby Gold Jewellery Pearl Erring.

Turquoise Ruby Gold Jewellery Pearl Erring.

By Stone.

Often referred to as "Egyptian turquoise", Sinai material is typically the most translucent, and under magnification its surface structure is revealed to be peppered with dark blue discs not seen in material from other localities.

Turquoise Gold Jewellery Erring Kaan Baali.

Turquoise Gold Jewellery Erring Kaan Baali.

By Stone.

The turquoise is found in sandstone that is, or was originally, overlain by basalt. Copper and iron workings are present in the area. 

Turquoise Gold Katak Jewellery Necklace Set.

Turquoise Gold Katak Jewellery Necklace Set.

By Stone.

The two most important of these mines, from a historic perspective, are Serabit el-Khadim and Wadi Maghareh, believed to be among the oldest of known mines. The former mine is situated about 4 kilometres from an ancient temple dedicated to the deity Hathor.

Turquoise Diamond Pearl Jewellery Necklace.

Turquoise Diamond Pearl Jewellery Necklace.

By Stone.

Since at least the First Dynasty (3000 BCE) in ancient Egypt, and possibly before then, turquoise was used by the Egyptians and was mined by them in the Sinai Peninsula. This region was known as the Country of Turquoise by the native Monitu. There are six mines in the peninsula, all on its southwest coast, covering an area of some 650 km2 (250 sq mi).

Turquoise Gold Fashion Jewellery Erring.

Turquoise Gold Fashion Jewellery Erring.

By Stone.

A weathered and broken trachyte is host to the turquoise, which is found both in situ between layers of limonite and sandstone and amongst the scree at the mountain's base. These workings are the oldest known, together with those of the Sinai Peninsula. Iran also has turquoise mines in Semnan and Kerman provinces.

Turquoise Diamond Fashion Jewellery Erring.

Turquoise Diamond Fashion Jewellery Erring.

By Stone.

Persian turquoise from Iran

This deposit is blue naturally and turns green when heated due to dehydration. It is restricted to a mine-riddled region in Nishapur, the 2,012 m (6,601 ft) mountain peak of Ali-mersai near Mashhad, the capital of Khorasan Province, Iran.

Turquoise Diamond Gold Jewellery Ring.

Turquoise Diamond Gold Jewellery Ring.

By Stone.

Persian turquoise from Iran

This deposit is blue naturally and turns green when heated due to dehydration. It is restricted to a mine-riddled region in Nishapur, the 2,012 m (6,601 ft) mountain peak of Ali-mersai near Mashhad, the capital of Khorasan Province, Iran. 

Turquoise Gold Jewellery Necklace Set.

 Turquoise Gold Jewellery Necklace Set.

By Stone.

Cutting and grinding turquoise in Nishapur, Iran, 1973

Iran

Iran has been an important source of turquoise for at least 2,000 years. It was initially named by Iranians "pērōzah" meaning "victory", and later the Arabs called it "fayrūzah", which is pronounced in Modern Persian as "fīrūzeh". In Iranian architecture, the blue turquoise was used to cover the domes of palaces because its intense blue colour was also a symbol of heaven on earth.[citation needed]

Turquoise Gold Jewellery Erring.

Turquoise Gold Jewellery Erring.

By Stone.

Turquoise is nearly always cryptocrystalline and massive and assumes no definite external shape. Crystals, even at the microscopic scale, are exceedingly rare. Typically the form is vein or fracture filling, nodular, or botryoidal in habit. Stalactite forms have been reported. Turquoise may also pseudomorphously replace feldspar, apatite, other minerals, or even fossils. Odontolite is fossil bone or ivory that has been traditionally thought to have been altered by turquoise or similar phosphate minerals such as the iron phosphate vivianite. Intergrowth with other secondary copper minerals such as chrysocolla is also common.

Turquoise Mans Silver Jewellery Bracelet

Turquoise Mans Silver Jewellery Bracelet. 

By Stone.

In the Southwestern United States turquoise is almost invariably associated with the weathering products of copper sulfide deposits in or around potassium-feldspar-bearing porphyritic intrusives. In some occurrences alunite, potassium aluminium sulfate, is a prominent secondary mineral. Typically turquoise mineralization is restricted to a relatively shallow depth of less than 20 metres (66 feet), although it does occur along deeper fracture zones where secondary solutions have greater penetration or the depth to the water table is greater.

Turquoise Gold Jewellery Erring

Turquoise Gold Jewellery Erring .

By Mans Women Jewellery.

Turquoise is insoluble in all but heated hydrochloric acid. Its streak is a pale bluish white and its fracture is conchoidal,[3] leaving a waxy lustre. Despite its low hardness relative to other gems, turquoise takes a good polish. Turquoise may also be peppered with flecks of pyrite or interspersed with dark, spidery limonite veining.

Turquoise Pearl Jewellery Erring Baali

Turquoise Pearl Jewellery Erring Baali.

By Mans Women Jewellery.

The refractive index of turquoise (as measured by sodium light, 589.3 nm) is approximately 1.61 or 1.62; this is a mean value seen as a single reading on a gemological refractometer, owing to the almost invariably polycrystalline nature of turquoise. A reading of 1.61–1.65 (birefringence 0.040, biaxial positive) has been taken from rare single crystals. An absorption spectrum may also be obtained with a hand-held spectroscope, revealing a line at 432 nm and a weak band at 460 nm (this is best seen with strong reflected light). Under longwave ultraviolet light, turquoise may occasionally fluoresce green, yellow or bright blue; it is inert under shortwave ultraviolet and X-rays.

Turquoise Gold Jewellery Necklace Set

Turquoise Gold Jewellery Necklace Set 

By Mans Women Jewellery.

The lustre of turquoise is typically waxy to subvitreous, and its transparency is usually opaque, but may be semitranslucent in thin sections. Colour is as variable as the mineral's other properties, ranging from white to a powder blue to a sky blue, and from a blue-green to a yellowish green. The blue is attributed to idiochromatic copper while the green may be the result of either iron impurities (replacing aluminium) or dehydration.

Turquoise Gold Jewellery Necklace Set

Turquoise Gold Jewellery Necklace Set

By Mans Women Jewellery

The finest of turquoise reaches a maximum Mohs hardness of just under 6, or slightly more than window glass. Characteristically a cryptocrystalline mineral, turquoise almost never forms single crystals, and all of its properties are highly variable. X-ray diffraction testing shows its crystal system to be triclinic.] With lower hardness comes lower specific gravity (2.60–2.90) and greater porosity; these properties are dependent on grain size.

Turquoise Erring Diamond Jewellery

Turquoise Erring Diamond Jewellery 

The gemstone has been known by many names. Pliny the Elder referred to the mineral as callais (from Ancient Greek κάλαϊς) and the Aztecs knew it as chalchihuitl . The word turquoise dates to the 17th century and is derived from the French turquois for "Turkish" because the mineral was first brought to Europe through Turkey, from mines in the historical Khorasan Province of Persia.

Gold Firoza Turquoise Jhumki Jewellery

Gold Firoza Turquoise Jhumki Jewellery

Turquoise

Turquoise-40031.jpg

General

Category Phosphate minerals

Formula

(repeating unit) CuAl6(PO4)4(OH)8·4H2O

Strunz classification 8.DD.15

Crystal system Triclinic

Crystal class Pinacoidal (1)

(same H–M symbol)

Identification

Colour Turquoise, blue, blue-green, green

Crystal habit Massive, nodular

Cleavage Good to perfect_usually N/A

Fracture Conchoidal

Mohs scale hardness 5–6

Luster Waxy to subvitreous

Streak Bluish white

Specific gravity 2.6–2.9

Optical properties Biaxial (+)

Refractive index nα = 1.610

nβ = 1.615

nγ = 1.650

Birefringence +0.040

Pleochroism Weak

Fusibility Fusible in heated HCl

Solubility Soluble in HCl

References