RECENT FROM Gold

Largest Gold Nuggets Discovered: Welcome Stranger And Hand Of Faith...

Gold nuggets are naturally occurring large masses of native gold found in alluvial deposits. Often they are concentrated by watercourses and recovered by placer mining. In other instances, gold nuggets are found in piles of residue in sites where mining operations once took place. Two gold nuggets are noted for being the largest masses of gold ever discovered. These are the “Welcome Stranger” and the “Hand of Faith”. Their respective “largest” titles, however, carry further qualifications. The Welcome Stranger Gold Nugget: The exact distinction given of this gold nugget is: “the largest alluvial gold nugget ever found”. It was discovered on February 5, 1869 at Moliagul, a small township...

RECENT FROM Precious Metals

Ruthenium: Most Versatile Of The Platinum Group Metals...

Arranged by name alphabetically, ruthenium is the last of six metallic elements in the platinum group. This precious metal is characterized as being both polyvalent and versatile. In fact, it is known to be more versatile than any of the other five precious metals in the platinum group. A hard, white metal, ruthenium is known to have four crystal modifications. While it does not tarnish under normal temperature, it does oxidize readily when exposed to air. It can be plated by means of two methods: thermal decomposition and electrodeposition. Following is a list of some of the properties of ruthenium: General: • Chemical Symbol: Ru • Atomic Number: 44...

RECENT FROM Silver

Silver: Precious Metal With The Highest Thermal And Electrical Conductivity...

Silver is generally described as a soft, white, lustrous metallic chemical element. It occurs naturally in its pure form, as an alloy with other metallic elements (especially gold), and in chlorargyrite and other minerals. As one of three coinage metals (the other two being copper and gold), silver is very malleable and ductile. Of the different metals, silver is known to have the highest thermal conductivity. Similarly of the different known elements, silver has the highest electrical conductivity. Provided below are some of the properties of this precious metal. General: • Chemical Symbol: Ag • Atomic Number: 47 • Category (as an element): Transition Metal • Group/ Period/ Block...

Three Methods Of Assay For Raw Precious Metals...

Items of jewelry or art made of precious metals are hallmarked based on specific requirements either of the country of import or the place of manufacture

posted on: Aug 3, 2014 | author: admin

The Six Precious Metals Of The Platinum Group...

In the periodic table of elements, six metallic elements are bunched together in the d-block, specifically in groups 8 to 9, periods 5 and 6.

posted on: Aug 3, 2014 | author: admin

The Four Platinum Bullion Coins: A Brief Description Of Each...

Bullion coins are coins made from precious metals. Their market values are determined by their inherent precious metal contents

posted on: Aug 3, 2014 | author: admin

The Eight Precious Metals Considered Noble Metals...

Most metallic chemical elements are known to easily oxidize and corrode, especially at high temperatures.

posted on: Aug 3, 2014 | author: admin

Silver: Precious Metal With The Highest Thermal And Electrical Conductivity...

posted on: Aug 3, 2014 | author: admin

Silver is generally described as a soft, white, lustrous metallic chemical element. It occurs naturally in its pure form, as an alloy with other metallic elements (especially gold), and in chlorargyrite and other minerals. As one of three coinage metals (the other two being copper and gold), silver is very malleable and ductile. Of the different metals, silver is known to have the highest thermal conductivity. Similarly of the different known elements, silver has the highest electrical conductivity. Provided below are some of the properties of this precious metal. General: • Chemical Symbol: Ag • Atomic Number: 47 • Category (as an element): Transition Metal • Group/ Period/ Block (in the Periodic Table): 11/ 5/ d • Atomic Weight: 107.8682 g.mol-1 • Electron Configuration: [Kr] 4d10 5s1 Physical: • Density (near room temperature): 10.49 g.cm-3 • Liquid Density (at melting point): 9.320 g.cm-3 • Melting Point: 961.78°C, 1234.93°F, 2041.4°K...

Safety Issues Concerning Precious Metals

posted on: Aug 3, 2014 | author: admin

The metallic chemical elements collectively known as precious metals are called as such because of their extreme rarity and high economic value. Precious metals occur naturally or are by-products of the processing of other less rare metals. In order of increasing mass abundance (parts per billion), the precious metals are rhenium, rhodium, iridium, ruthenium, osmium, gold, platinum, palladium, and silver. These metals are not radioactive and are mostly used for industrial purposes and for jewelry. Still, precious metals have some safety issues attached to them: Rhenium: Since rhenium is used in very small amounts, its toxicity is virtually unknown. The hazardous property of rhenium halide, for example, may be attributed either to rhenium itself or to the other elements that make up the compound. Another rhenium compound – potassium perrhenate – is known to have a median lethal dose much like that of sodium chloride (commonly known as table...

Ruthenium: Most Versatile Of The Platinum Group Metals...

posted on: Aug 3, 2014 | author: admin

Arranged by name alphabetically, ruthenium is the last of six metallic elements in the platinum group. This precious metal is characterized as being both polyvalent and versatile. In fact, it is known to be more versatile than any of the other five precious metals in the platinum group. A hard, white metal, ruthenium is known to have four crystal modifications. While it does not tarnish under normal temperature, it does oxidize readily when exposed to air. It can be plated by means of two methods: thermal decomposition and electrodeposition. Following is a list of some of the properties of ruthenium: General: • Chemical Symbol: Ru • Atomic Number: 44 • Category (as an element): Transition Metal • Group/ Period/ Block (in the Periodic Table): 8/ 5/ d • Atomic Weight: 101.07 g.mol-1 • Electron Configuration: [Kr] 4d7 5s1 Physical: • Density (near room temperature): 12.45 g.cm-3 • Liquid Density...

Rhodium: Costliest Precious Metal

posted on: Aug 3, 2014 | author: admin

In 1803, the English physicist and chemist William Hyde Wollaston discovered a chemical element that is today considered the most expensive of the precious metals. This precious metal, which belongs to the platinum group metals, is rhodium. With its current price of around 1,000 U.S. dollars per troy ounce, rhodium is about five times costlier than platinum. Wollaston’s discovery of rhodium was made possible with the use of crude platinum ore. He first dissolved the ore in nitro-hydrochloric acid (also called aqua regia) and neutralized the acid with lye (or sodium hydroxide). By adding salmiac (ammonium chloride), he then precipitated the platinum. All other metals, including rhodium, were precipitated with zinc. Rhodium was further precipitated by the addition of sodium chloride. Finally, it was washed with ethanol and reacted with zinc, forming the precious metal that it is known today. Since rhodium occurs in ores mixed with other metals...

« Previous Entries