Rocawear

Rocawear has clothing lines and accessories for men, women and children.Its main funders currently are Mareed Clothing Line. According to Rebbenu Bachya, the word "Sapir" in the verse Exodus 28:20 means "Sapphire" and was the stone on the Ephod representing the tribe of Issachar. Rocawear is an urban clothing label created in 1999 by Damon Dash & Jay-Z, heads of the hip hop label Roc-a-Fella Records. The major deposits are: Sri Lanka, Thailand, Burma, Cambodia, Nigeria, Madagascar and Australia. It refers to a "blue gem," either the sapphire proper or possibly lapis lazuli. The word sapphire is probably Phoenician in origin, coming to English from the Ancient Greek word σάπφειρος, through the Latin sapphirus.

Wafers of single crystal sapphire are also used in the semiconductor industry as a substrate for the growth of gallium nitride based blue and green light emitting diodes. Such slices are used as watch faces in high quality watches, as the material's exceptional hardness makes the face almost impossible to scratch. Pure sapphire ingots can be sliced into wafers and polished to form transparent crystal slices. In these lasers, a synthetically produced sapphire crystal with chromium or titanium impurities is irradiated with intense light from a special lamp, or another laser, to create stimulated emission.

It can also be easily modelocked. While this laser has few commercial applications, the Ti-sapphire laser is popular due to the relatively rare ability to tune the laser wavelength in the red-to-near infrared region of the electromagnetic spectrum. The first ever laser produced was based on the ruby chromium impurity in sapphire. As well as gemstone applications there are many other uses:.

Synthetic sapphire crystals can be grown in cylindrical crystal ingots of large size, up to many inches in diameter. Sapphire is also the birthstone associated with September. Cornflower blue is one of the most popular colors for sapphires (the other choice color a deep royal blue), though there is little objective consensus about which shade of blue is the most cornflower or the most desirable. Lady Diana Spencer's engagement ring from Charles, Prince of Wales was a sapphire ring.

It weighs 423 carats (84.6 g). The Logan sapphire is one of the largest blue sapphire gems known. A manufactured star sapphire called the Linde Star shows a very regularly-shaped and distinct asterism because the formation process is more tightly controlled than it is in nature. Although natural sapphires can show an asterism, the shape of the star is usually somewhat irregular and sometimes indistinct.

A version which shows an asterism is called a Star sapphire (see picture above). The tell-tale sign of synthetic sapphires is the crystalline growth lines which are usually curved due to the pulling during the accelerated crystal growth process. The chemical compositions and physical properties are identical to the natural sapphires. Gem quality sapphires and rubies occur naturally and can be easily and cheaply produced in the laboratory.

They have a hardness of 9 on the Mohs hardness scale (Diamond is 10). The crystals are exceptionally hard, with only diamond being harder among natural gems. Traces of iron and titanium give sapphires a blue color. Pure sapphire is transparent.

It is the impurities in the aluminium oxide crystal that give the color variations, with different impurity chemical elements giving the different colors that can be found. They were found in many countries especially in Asia such as India, Sri Lanka, Thailand, Myanmar, and Cambodia. However a pink-orange sapphire, called a padparadsha, is highly prized. Pink, yellow, green, white, and parti-color (multi-colored) sapphires are often valued less than the blue variety of the same quality and size.

When color is not specified, sapphire refers to the blue variety. (The red variety of corundum is also known as ruby.). Sapphire is any gemstone-quality corundum that is not red. .

It can be found naturally as gemstones or manufactured in large crystal boules for a variety of applications. Sapphire is the single-crystal form of aluminium oxide (Al₂O₃), a mineral known as corundum.