Psychic (sī'kĭk) refers in part to the human mind or psyche (ex. "psychic turmoil"). In popular usage the term psychic usually denotes paranormal forces and influences, or abilities such as psychokinesis and extra-sensory perception. People said to be sensitive to, or able to use, these paranormal forces are called psychics. The term also refers to stage magicians, mentalists, and charlatans who perform psychic-like illusions without paranormal abilities.

Belief in paranormal psychic phenomena is common. A survey conducted by the Gallup Organization in 2005 suggested that 41% of the general United States population had a belief in extra-sensory perception.^[1]

The existence of paranormal psychic abilities is highly controversial. Parapsychology explores this possibility, but no evidence for paranormal phenomena has gained wide acceptance in the mainstream scientific community.

SOURCE: WIKIPEDIA

Ruby is a red gemstone that varies from a light pink to a blood red, a variety of the mineral corundum (aluminium oxide). The color is caused mainly by chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires. It is considered one of the four precious stones, together with the sapphire, the emerald and the diamond.

Rubies are mined in Africa, Asia, Australia, Greenland, Madagascar and North Carolina. They are most often found in Myanmar (Burma), Sri Lanka, Tanzania, Kenya, Madagascar, and Cambodia, but they have also been found in the U.S. states of Montana, North Carolina and South Carolina. The Mogok Valley in Upper Myanmar has produced some of the finest rubies but, in recent years, very few good rubies have been found there. The unique color in Myanmar (Burmese) rubies is described as "pigeon’s blood". They are known in the trade as “Mogok” rubies. In central Myanmar the area of Mong Hsu also produces rubies. The latest ruby deposit to be found in Myanmar is situated in Nam Ya. In 2002 rubies were found in the Waseges River area of Kenya. Sometimes spinels are found along with rubies in the same rocks and are mistaken for rubies. However, fine red spinels may approach the average ruby in value.

Rubies have a hardness of 9.0 on the Mohs scale of mineral hardness. Among the natural gems only diamond is harder (Mohs 10.0 by definition).

A cut ruby.

All natural rubies have imperfections in them, including color impurities and inclusions of rutile needles known as "silk". Gemologists use these needle inclusions found in natural rubies to distinguish them from synthetics, simulants, or substitutes. Usually the rough stone is heated before cutting. Almost all rubies today are treated in some form (of which heat treatment is the most common practice), and rubies which are completely untreated and still of excellent quality command a large premium. In general we can list the following types of improvements: color alteration, improving transparency by dissolving rutile inclusions, healing of fractures (cracks) or even completely filling them. See Treatments below.

Prices of rubies are primarily determined by color (the brightest and best "red" called Pigeon Blood Red, command a huge premium over other Rubies of similar quality). After Color follows clarity: similar to Diamonds, a clear stone will command a premium, but a Ruby without any needle-like rutile inclusions will indicate the stone has been treated one way or another. Cut and Carat (size) also determine the price approximately like clarity does.

SOURCE: WIKIPEDIA

RALPH GIRON

Synthetic sapphire

Synthetic sapphire crystals can be grown in cylindrical crystal boules of large size, up to many inches in diameter. As well as gemstone applications there are many other uses:

The first ever laser produced was based on the ruby, the red variety of corundum. While this laser has few 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. It can also be easily modelocked. 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.

Pure sapphire boules can be sliced into wafers and polished to form transparent crystal slices. Such slices are used as watch faces in high quality watches, as the material's exceptional hardness makes the face resistant to scratching. Since sapphire ranks a 9 on the Mohs Scale, owners of such watches should still be careful to avoid exposure to diamond jewelry, and should avoid striking their watches against artificial stone and simulated stone surfaces. Such surfaces often contain materials including silicon carbide, which, like diamond, are harder than sapphire and thus capable of causing scratches (Scheel 2003).

Sapphire is highly transparent at wavelengths of light between 170 nm to 5.3 μm, as well as being five times stronger than glass. This leads to use of synthetic sapphire windows in high pressure chambers for spectroscopy.

Wafers of single crystal sapphire are also used in the semiconductor industry as a substrate for the growth of gallium nitride based devices.

Cermax Xenon arc lamp with synthetic sapphire output window

One type of Xenon Arc Lamp known as Cermax (original brand name - generically known as a ceramic body xenon lamp) use sapphire output windows that are doped with various other elements to tune their emission. In some cases, the UV emitted from the lamp during operation causes a blue glow from the window after the lamp is turned off. It is approximately the same color as Cherenkov radiation but is caused by simple phosphorescence.

RALPH GIRON

SOURCE: WIKIPEDIA =))