Sapphire is a gemstone variety of the mineral corundum, an aluminum oxide, when it is a color other than red or dark pink, in which case the gem would be a ruby, considered a different gemstone. Trace amounts of other elements such as iron, titanium, or chromium can give corundum blue, yellow, pink, purple, orange, or greenish color. Pink-orange sapphires are padparadscha. Pure chromium is the distinct impurity of rubies. However, a combination of e.g. chromium and titanium can give a sapphire of a color distinct from red. Sapphires are a part of many jewelry settings. Sapphires found naturally by searching through certain sediments or rock formations, or manufactured for industrial or decorative purposes in large crystal boles. Because of the remarkable hardness of sapphires , sapphires are used in some non-ornamental applications, including infrared optical components, such as in scientific instruments; small, high-durability windows ; wristwatch crystals; and very thin electronic wafers, which are used as the insulating substrates of very special-purpose solid-state electronics . The sapphire is one of the two or three gem-varieties of corundum, with another one being the red or deep pink ruby. Although blue is their most known color, sapphires make up of any color of corundum except for red. Sapphires may also be colorless, and found in shades of gray and black. The cost of natural sapphires varies depending on their color, clarity, size, cut, and overall quality - as well as their geographic origin, oddly enough. Significant sapphire deposits are found in Eastern Australia, Thailand, Sri Lanka, Madagascar, East Africa, and in North America in a few locations, such as at Gem Mountain, and in or near the Missouri River in the region around Helena, Montana. Sapphire and rubies found together in the same area, but one gem is usually more abundant. Color in gemstones breaks down into three components: hue, saturation, and tone. Hue is the color of the gemstone. Saturation refers to the vividness, brightness, or colorfulness of the hue and tone is the lightness to darkness of the hue. Blue sapphire exists in various mixtures of its primary and secondary hues, various tonal levels and at various levels of saturation. Blue sapphires evaluated based upon the purity of their primary hue. Purple, violet, and green are the most common secondary hues found in blue sapphires. Violet and purple can contribute to the overall beauty of the color, while green considered distinctly negative. Blue sapphires with up to 15% violet or purple are to be of fine quality. Blue sapphires with any amount of green as a secondary hue are not fine quality. Gray is the normal saturation modifier or mask found in blue sapphires. Gray reduces the saturation or brightness of the hue and therefore has a distinctly negative effect. The color of fine blue sapphires described as a vivid medium dark violet to purplish blue where the primary blue hue is at least 85% and the secondary hue no more than 15% without the least admixture of a green secondary hue or a gray mask. Yellow and green sapphires found regularly. Pink sapphires deepen in color as the quantity of chromium increases. The deeper the pink color the higher their monetary value as long as the color is trending towards the red of rubies. Sapphires also occur in shades of orange, brown, and colorless sapphires sometimes used as diamond substitutes in jewelry. Padparadscha sapphires often draw higher prices than many of even the finest blue sapphires. Recently, more sapphires of this color have appeared on the market result of a new artificial treatment method that is lattice diffusion.

American Silver Eagle

The American Silver Eagle is the official silver bullion coin of the United States of America. The United States Mint first released it in November 1986. It struck only in the one-troy ounce size, which has a face value of 1 dollar and guaranteed to contain one troy ounce of 99.9% pure silver. The United States Mint certifies its content, purity, and weight. Silver Eagle bullion coins, along with American Gold Eagle bullion coins are viable investment alternatives to the gold and silver bullion coins produced by other countries. To ensure wide distribution of the coins, the United States Mint awarded a contract to Grey Advertising to assist in marketing and publicizing the coins domestically and internationally. The design on the coin's obverse taken from the "Walking Liberty" design by Adolph A. Weinman, which originally had been used on the Walking Liberty Half Dollar coin of the United States from 1916 to 1947. As this iconic design had been a public favorite—and indeed one of the most beloved designs of any United States coinage of modern times, silver or otherwise—it revived for the Silver Eagle decades later. The obverse inscribed with the year of minting or issuance, the word LIBERTY, and the phrase IN GOD WE TRUST. The reverse is by John Mercanti and portrays a heraldic eagle behind a shield; the eagle grasps an olive branch in its right talon and arrows in its left talon, echoing the Great Seal of the United States; above the eagle are thirteen five-pointed stars representing the Thirteen Colonies. The reverse inscribed with the phrases UNITED STATES OF AMERICA, 1 OZ. FINE SILVER ONE DOLLAR, and E PLURIBUS UNUM as well as the applicable mintmark. Like the American Gold Eagle and American Platinum Eagle bullion coins, the United States Mint does not sell Silver Eagle bullion coins directly to the public. In order to provide "effective and efficient distribution, which maximizes the availability of the coins in retail markets as well as major investment markets" the Mint utilizes a network of authorized purchasers to distribute the coins. The coins sold in bulk at a premium over the spot price of silver. The coins sold to banks, brokerage companies, coin dealers, precious metal firms, and wholesalers that meet the following requirements. Be an experienced and established market maker in silver bullion coins. Provide a liquid two-way market for the coins. Be audited annually by an internationally accepted accounting firm. Have an established broad base of retail customers to which to distribute the coins. Have a tangible net worth of $5 million. Authorized purchasers must order a minimum of 25,000 coins, which they sell to secondary retailers that sell them, in turn, to the public.