Turquoise

Turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminium, with the chemical formula CuAl₆(PO
4)₄(OH)₈·4H
2O. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue. In recent times, turquoise, like most other opaque gems, has been devalued by the introduction of treatments, imitations, and synthetics onto the market.

The substance has been known by many names, but the word turquoise, which dates to the 17th century, is derived from the French turques for "Turks", because the mineral was first brought to Europe from Turkey, from mines in the historical Khorasan Province of Persia.Pliny the Elder referred to the mineral as callais and the Aztecs knew it as chalchihuitl.

Properties of turquoise

The finest of turquoise reaches a maximum 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. Its crystal system is proven to be triclinic via X-ray diffraction testing. With lower hardness comes lower specific gravity (2.60–2.90) and greater porosity: These properties are dependent on grain size. The lustre of turquoise is typically waxy to subvitreous, and 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 (disambiguation)

Turquoise is a gemstone.

Turquoise may also refer to:

Turquoise (trading platform)

Turquoise is an equities trading platform (Multilateral trading facility or MTF), created by nine major investment banks in 2008. The aim was to provide dealing services at a 50% discount to traditional exchanges. It is a hybrid system that allows trading both on and off traditional exchanges. The system was advertised as a "pan-European platform based in London".

History

It was set up by a consortium of banks made up of BNP Paribas, Citi, Credit Suisse, Deutsche Bank, Goldman Sachs, Merrill Lynch, Morgan Stanley, Société Générale and UBS. The group selected EuroCCP to provide clearing and settlement services. The group selected Sweden's Cinnober as its trading platform. Turquoise developed a real-time market surveillance system "to capture breaches of trading rules and root out market irregularities". The system is based on the Progress Apama complex event processing platform. Turquoise was successfully launched on 15 August 2008.

On 21 December 2009, the London Stock Exchange Group agreed to take a 60% stake in trading platform Turquoise, which had a 7% share of the market. Turquoise was merged with the LSE's trading facility Baikal Global.

Believe (Emerson Drive album)

Believe is the sixth studio album by Canadian country music group Emerson Drive. The album was released in Canada on May 5, 2009 via Midas/Valory/Open Road. The album's first single, "Belongs to You," reached the top forty on the Billboard Hot Country Songs chart in the United States.

Critical reception

The album received mixed reviews from music critics. It received a three-and-a-half star rating from Todd Sterling of AllMusic, who said that the album was "slickly produced" and that it "sticks to the well-worn formula of the group's previous releases," but said that it had "every color of the musical rainbow." Sterling cited "Your Last" as a standout, calling it a "lump-in-the-throat masterpiece." Jim Malec of The 9513 gave it one star out of five, referring to the song's lyrics as largely cliché in nature and saying, "There is not a single song on Believe worth hearing. It is an entirely disposable album that is unoriginal, uninteresting and unnecessary." Malec also criticized the album's sound, saying that the mixing of instruments and Brad Mates' vocals did not seem cohesive.

Believe (Elton John song)

"Believe" is a 1994 song recorded by Elton John. It was the first single from his album Made in England and was released on 20 February 1995. It reached #1 in Canada. In the US, "Believe" was Elton John's fifteenth number one on the Adult Contemporary chart and also went to number thirteen on the Billboard Hot 100. It gave him his third straight top twenty single in the US, with his two hit singles from Disney's The Lion King preceding it. In Europe, it was a top twenty hit in Switzerland, UK, France and Belgium (Wallonia) and achieved moderate success in several other countries. The songs which feature as B-side were recorded at the Greek Theatre, in Los Angeles.

The music video for the song was entirely in black-and-white and shot in London, featuring shots of the Believe Wall in the beginning and end of the video.

Track listings

Ocean Avenue (album)

Ocean Avenue is the fourth studio album by the American rock band Yellowcard. The album was the band's major-label debut and brought them to prominence. It was a commercial success in the United States, led by titular hit single "Ocean Avenue". The album received generally positive reviews from music critics and has been certified platinum in sales by the RIAA and gold by the CRIA. It was produced by Neal Avron, and released on July 22, 2003 through Capitol Records.

In 2013, the band released an acoustic version of the album, Ocean Avenue Acoustic, in honor of the album's tenth anniversary.

Commercial performance and promotion

Ocean Avenue sold 11,000 copies in its first week in the U.S., debuting at #23. It is Yellowcard's most successful album and has been certified Platinum for sales in excess of 1,000,000. It was released as an enhanced CD in some countries. The enhanced CD includes a video entitled "The Making of Ocean Avenue" and a previously unreleased video of the song "Powder" (from The Underdog EP). In 2005, the album was released as a Special Edition in Malaysia, with live videos and music videos. The album was re-released on limited edition vinyl in 2011.