From ArticleWorld

Sapphires are single-crystal in structure, formed of aluminum oxide (Al2O3 ) and grouped under the mineral corundum. Australia produces the largest amount of natural sapphires. Nearly all shades of blue are applicable to sapphires, but ideally a strong blue is the finest shade of all. Less commonly found are sapphires in the colors of pink, yellow, violet, green and colorless. They are known as 'fancy sapphires'. Yet only blue is associated with sapphires because blue sapphires are more easily found and recognized.

Synthetic sapphire and non-gemstones applications

Sapphires have many uses aside from decoration. Some of them are discussed below.

Sapphires were used to produce the first laser because of the ruby chromium impurities found in them. More recently, the more useful and popular 'Ti-sapphire laser' is used to tune the wavelength in the infrared region of the electromagnet spectrum. It can also be mode-locked or phase-locked. Lasers made with the chromium or titanium impurities in crystal sapphire are specialized to create stimulated emission when treated with intense light from another light source.

Synthetic sapphires are used to produce crystal brick such as structures called ingots. These ingots are sliced into wafers to make the faces for high quality watches. Sapphires are hard and measure 9 on Moh's scale, but they are not as hard as the diamond and other artificial stones containing silicon carbide. It is therefore advised that owners of watches with sapphire faces avoid hitting their watches on all stone surfaces.

Sapphires are used as substrate in semi-conductor industries for the growth of gallium nitrite-based blue and green light-emitting diodes.

Historical and cultural references

Sapphires are believed to have mystical qualities and are made reference to in the Bible.

The sapphire is considered to be the 'stone of destiny' because it bestows wealth and promotes mental clarity and perception.

Sapphire in Greek means 'blue'; blue symbolizes spirituality and divine favor. It is the token of joyful devotion for the love of God. That is why Moses was given the 10 commandments on tablets of sapphire, which indicated the purity and sacredness of the gemstone. Most kings' crowns are studded with sapphires to signify wisdom, purity and divinity.

Sapphires symbolize the virtues of faithfulness, truth and sincerity. In 'The Legend of Zelda; Ocarina of Time', the sapphire was used as one of the three spiritual stones and as an engagement ring to Link from princess Ruto. Because of these virtues, this gemstone was the first choice for an engagement ring, and the tradition was revived with Prince Charles' engagement ring for Princess Diana.

According to Rebbenu Bachya, 'sapir' means sapphire and it is mentioned in a verse of Exodus as being one of the stones in the ephod that represented the tribe Issachar. Aside from its spiritual and historical significance, it is believed that a sapphire acts as a healer for a sore throat when placed around the neck.

Sapphire is also the birth stone for September and April, as well as the gemstone for Taurians.