Most Precious Wood

---

Opal is a hydrated amorphous form of silica (SiO2·nH2O); its water content may range from 3% to 21% by weight, but is usually between 6% and 10%. Due to the amorphous (chemical) physical structure, it is classified as a mineraloid, unlike crystalline forms of silica, which are considered minerals. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl, and basalt. The name opal is believed to be derived from the Sanskrit word upala (उपल), which means 'jewel', and later the Greek derivative opállios (ὀπάλλιος). There are two broad classes of opal: precious and common. Precious opal displays play-of-color (iridescence); common opal does not. Play-of-color is defined as "a pseudo chromatic optical effect resulting in flashes of colored light from certain minerals, as they are turned in white light." The internal structure of precious opal causes it to diffract light, resulting in play-of-color. Depending on the conditions in which it formed, opal may be transparent, translucent, or opaque, and the background color may be white, black, or nearly any color of the visual spectrum. Black opal is considered the rarest, while white, gray, and green opals are the most common.

---

Article title : Opal
"official gemstone of Nevada. Most of the precious opal is partial wood replacement. The precious opal is hosted and found in situ within a subsurface horizon..."
Article title : Belshazzar's Feast (Walton)
"Of precious stones, of pearls, of fine linen, Of purple, silk and scarlet, All manner vessels of ivory, All manner vessels of most precious wood, Of..."
Article title : Revelation 18
"wood, and all manner vessels of ivory, and all manner vessels of most precious wood, and of brass, and iron, and marble, 13 And cinnamon, and odours,..."
Article title : Ancient furniture
"make chariots during the 18th Dynasty. One of the most precious woods in Egypt was walnut wood. This wood was imported from the Mediterranean Coast, and..."
Article title : Marjorie Morningstar (film)
"warbles 'A Very Precious Love,' the film's theme number." Times critiques of the other performances: "Carolyn Jones, as Miss Wood's best friend, makes..."
Article title : Gollum
"cousin Déagol, who found it in the River Anduin. Gollum called the Ring "my precious", and it extended his life far beyond natural limits. Centuries of the..."
Article title : Lenny Kravitz
"Rock". Aside from his music career, Kravitz has acted in films including Precious (2009) and the first two installments of The Hunger Games film series (2012–13)..."
Article title : Church of the Most Precious Blood, Southwark
"Commons has media related to Church of the Most Precious Blood, Southwark. The Church of the Most Precious Blood is a Roman Catholic church in the Archdiocese..."
Article title : Amber
"Illyrian amber jewellery List of types of amber Petrified wood Pearl Poly(methyl methacrylate) Precious coral In Latin the name succinum was unambiguously used..."
Article title : Peridot
"of forsterite, the variety most often used to cut peridot gems, are rare; as a result, peridot is considered to be precious. In the ancient world, peridot..."

---