american express

american express mastercard visausps logoups logo   

24k Gold information/precious and semi-precious stones

The Following information is provided for you below - 24k gold, 18k gold, 14k gold - yellow, green and pink.  Precious stones and semi-precious stones from around the world.

Today's 24K Gold Market Price

(1) 24k Gold
(2) 22k Gold
(3) 18k gold
(4) 14K gold
(5) 14K green gold
(6) 14K pink gold
(7) 24k gold's contribution
Physical Characteristics
Extraction and Refining
Mining Gold
Grinding Gold
Precious Stones: Diamonds
The Four "C''s are:
Precious Stones: Emeralds
Precious Stones: Rubies
Precious Stones: Sapphires
(20) GIA* Color Grading Scale
(21) Semi-Precious Stones: Amethyst
(22) Semi-Precious Stones: Swiss Blue Topaz
(23) Semi-Precious Stones: Garnet
(24) Semi-Precious Stones: Honey Citrine
(25) Semi-Precious Stones: Peridot
(26) Synthetic Stones: Faux Diamonds - Cubic Zirconia

(27) Freshwater Pearls

(1) 24k Gold is a very soft and malleable metal in its pure form.  It can be made slightly harder by drawing the metal through a jewelers draw plate. 24k gold can also be rolled through a rolling mill.  24k gold is extremely soft when annealed for inlay jewelry work.  To join pieces of 24k gold, they should be fused.  We use 24k gold in Mark Ehrmann Jewelry Designs Keum-bu line of jewelry. 24k Gold is available in casting grain, sheet, round wire, coins-Ancient Byzantine gold coins and gold bullion coins, 1 oz disc, and bullion from 5-100 ozs.  The beauty of 24k gold is that one may also invest in gold bullion. 24K pure gold has a chemical symbol of Au, it melts at 1945 degrees Fahrenheit its specific gravity is 19.32 and its weight is 10.180 in Troy ounces.

(2) 22k Gold has the 24k gold look but is made harder for jewelry and dental use by adding 8.3% alloy.  22k gold can easily be textured and formed into beautiful jewelry.  22k gold can be easily fused or soldered with 21k gold solder.  American Eagle gold coins are stamped by the United States Mint and are made with 22k gold. (1.000 oz gold, 0.091 oz alloy). 22K gold is also available in casting grain, sheet, round wire, sizing wire and bezel wire.  22k gold is also used in the process of granulation.

(3) 18k gold is .752 fine, which is the European standard of 18/24k gold and 6/24 alloy.  18K gold products are shanks for rings, stone settings, sheet, wires, bezels, grain, and tubing.  There is also an 18k royal yellow gold that has more of an Italian gold color which looks a little more green.

(4) 14K gold is .585 fine and is the most used gold alloy in the United States. Rings, necklaces, pendants,earrings, bracelets primarily made from 14k gold.  14k gold has less than 4% zinc which makes it suitable for enameling jewelry.

(5) 14K green gold contains gold, silver, copper and zinc.  Copper is the main hardening agent in karat gold's (nickel in white gold's) but since it is used in such a small percentage in green gold, these alloys are softer than karat gold's in other colors.  The greenest metal is obtained by alloying to 18 karat.  This also produces the softest green gold so there usually is no need to anneal 18K green.  14k green is popular because it provides a nice contrast when grouped with pink and white gold.

(6) 14K pink gold contain the same metals as yellow gold, which are gold, silver, copper, and zinc.  The pink color comes from a higher percentage of copper in the alloy.  Pink gold's anneal the same way as yellow gold's.  To anneal 14k gold, heat metal to cheery red color (1400 degrees F) and then quench or let metal air cool.  The hardness in the different karats of pink gold also resemble yellow gold.  Pink gold produces are becoming fashionable.  Pink gold is available in casting grain, sheet, bezel strip, round wire, and sizing wires.

(7) 24k gold's contribution to the history of Mankind

Gold, recognizable by its yellowish cast, is one of the oldest metals used by humans. As far back as the Neolithic period, humans have collected gold from stream beds, and the actual mining of gold can be traced as far back as 3500 B.C., when early Egyptians (the Sumerian culture of Mesopotamia) used mined gold to craft elaborate jewelry, religious artifacts, and utensils such as goblets.    

Gold's aesthetic properties combined with its physical properties have long made it a valuable metal. Throughout history, gold has often been the cause of both conflict and adventure: the destruction of both the Aztec and Inca civilizations, for instance, and the early American gold rushes to Georgia, California, and Alaska.    

The largest deposit of gold can be found in South Africa in the Precambrian Witwatersrand Conglomerate. This deposit of gold ore is hundreds of miles across and more than two miles deep. It is estimated that two-thirds of the gold mined comes from South Africa. Other major producers of gold include Australia, the former Soviet Union, and the United States (Arizona, Colorado, California, Montana, Nevada, South Dakota, and Washington).  Without the discovery of gold in Nevada, it has been stated that the Union would not have been able to fund the army and all the military campaigns that would eventually win the Civil War.  

About 65 percent of processed gold is used in the arts industry, mainly to make jewelry. Besides jewelry, gold is also used in the electrical, electronic, and ceramics industries. These industrial applications have grown in recent years and now occupy an estimated 25 percent of the gold market. The remaining percentage of mined gold is used to make a type of ruby colored glass called purple of Cassius, which is applied to office building windows to reduce the heat in the summer, and to mirrors used in space and in electroscopes so that they reflect the infrared spectrum.

(8) Physical Characteristics

Gold, whose chemical symbol is Au, is malleable, ductile, and sectile, and its high thermal and electrical conductivity as well as its resistance to oxidation make its uses innumerable. Malleability is the ability of gold and other metals to be pressed or hammered into thin sheets, 10 times as thin as a sheet of paper. These sheets are sometimes evaporated onto glass for infrared reflectivity, molded as fillings for teeth, or used as a coating or plating for parts. Gold's ability to be drawn into thin wire (ductility) enables it to be deposited onto circuits such as transistors and to be used as an industrial solder and brazing alloy. For example, gold wire is often used for integrated circuit electrical connections, for orthodontic and prosthetic appliances, and in jet engine fabrication.

Gold's one drawback for use in industry is that it is a relatively soft metal (sectile). To combat this weakness, gold is usually alloyed with another member of the metal family such as silver, copper, platinum, or nickel. Gold alloys are measured by karats (carats). A karat is a unit equal to 1/24 part of pure gold in an alloy. Thus, 24 karat (24K) gold is pure gold, while 18 karat gold is 18 parts pure gold to 6 parts other metal.

(9) Extraction and Refining

Gold is usually found in a pure state; however, it can also be extracted from silver, copper, lead and zinc. Seawater can also contain gold, but in insufficient quantities to be profitably extracted—up to one-fortieth (1/40) of a grain of gold per ton of water. Gold is generally found in two types of deposits: lode (vein) or placer deposits; the mining technique used to extract the gold depends upon the type of deposit. Once extracted, the gold is refined with one of four main processes: floatation, amalgamation, cyanidation, or carbon-in-pulp. Each process relies on the initial grinding of the gold ore, and more than one process may be used on the same batch of gold ore.

(10) Mining Gold

In lode or vein deposits, the gold is mixed with another mineral, often quartz, in a vein that has filled a split in the surrounding rocks. Gold is obtained from lode deposits by drilling, blasting, or shoveling the surrounding rock.
Lode deposits often run deep underground. To mine underground, miners dig shafts into the ground along the vein. Using picks and small explosives, they then remove the gold ore from the surrounding rock. The gold ore is then gathered up and taken to a mill for refinement.

Placer deposits contain large pieces of gold ore (nuggets) and grains of gold that have been washed downstream from a lode deposit and that are usually mixed with sand or gravel. The three main methods used to mine placer deposits are hydraulic mining, dredging, and power shoveling. All methods of placer deposit mining use gravity as the basic sorting force.
In the first method, a machine called a "hydraulic giant" uses a high pressure stream of water to knock the gold ore off of banks containing the ore. The gold ore is then washed down into sluices or troughs that have grooves to catch the gold.

Dredging and power shoveling involve the same techniques but work with different size buckets or shovels. In dredging, buckets on a conveyor line scoop sand, gravel, and gold ore from the bottom of streams. In power shoveling, huge machines act like shovels and scoop up large quantities of gold-bearing sand and gravel from stream beds.

Hydraulic mining and dredging are outlawed in many countries because they are environmentally destructive to both land and streams.

(11) Grinding Gold

Once the gold ore has been mined, it usually is washed and filtered at the mine as a preliminary refinement technique. It is then shipped to mills, where it is first combined with water and ground into smaller chunks. The resulting mixture is then further ground in a ball mill—a rotating cylindrical vessel that uses steel balls to pulverize the ore.
Separating the gold from the ore

The gold is then separated from the ore using one of several methods. Floatation involves the separation of gold from its ore by using certain chemicals and air. The finely ground ore is dumped into a solution that contains a frothing agent (which causes the water to foam), a collecting agent (which bonds onto the gold, forming an oily film that sticks to air bubbles), and a mixture of organic chemicals (which keep the other contaminants from also bonding to the air bubbles). The solution is then aerated—air bubbles are blown in—and the gold attaches to the air bubbles. The bubbles float to the top, and the gold is skimmed off.
Cyanidation also involves using chemicals to separate the gold from its contaminants. In this process, the ground ore is placed in a tank containing a weak solution of cyanide. Next, zinc is added to the tank, causing a chemical reaction in which the end result is the precipitation (separation) of the gold from its ore. The gold precipitate is then separated from the cyanide solution in a filter press. A similar method is amalgamation, which uses the same process with different chemicals. First, a solution carries the ground ore over plates covered with mercury. The mercury attracts the gold, forming an alloy called an amalgam. The amalgam is then heated, causing the mercury to boil off as a gas and leaving behind the gold. The mercury is collected, recycled and used again in the same process.

The carbon-in-pulp method also uses cyanide, but utilizes carbon instead of zinc to precipitate the gold. The first step is to mix the ground ore with water to form a pulp. Next, cyanide is added to dissolve the gold, and then carbon is added to bond with the gold. After the carbon particles are removed from the pulp, they are placed in a hot caustic (corrosive) carbon solution, which separates the gold from the carbon.

If the gold is still not pure enough, it can be smelted. Smelting involves heating the gold with a chemical substance called flux. The flux bonds with the contaminants and floats on top of the melted gold. The gold is then cooled and allowed to harden in molds, and the flux-contaminant mixture (slag) is hauled away as a solid waste.
The Future

Because gold is a finite resource, its long-term future is limited. In the short term, however, it will continue to find widespread use in jewelry and in industrial applications, especially in the electronics field.

In the last few years, several companies have focused on extracting gold from sulphide ore rather than oxide ore. Previous techniques made such extraction difficult and expensive, but a newer technique called bio leaching has made extraction more feasible. The process involves combining the sulphide ore with special bacteria that "eat" the ore or break it down into a more manageable form.

(12) Precious Stones: Diamonds Cubic Zirconia

Diamonds are mined in many parts of the world, but 80% of the stones on the market today come from Angola, Australia, Botswana, Namibia, South Africa, Russia and Zaire. All of these sources might appear to indicate great availability, but this is not the case. More than 250 tons of ore need to be blasted, crushed and processed to yield just one carat of rough diamond. Most of the rough extracted from the ground is not suitable for gems; only about 20% of all rough diamonds are suitable for gem cutting.

Mohs Hardness: 10 /Refractive index:2.417 /Specific Gravity: 3.515 /Treatment: none

(13) The Four "C''s are:

Color-Diamonds can cover the entire spectrum of colors.  They range from having a perceptible yellow or brownish tint up to those rare diamonds described as colorless.  Colorless diamonds allow the most reflection of light and are therefore the most desirable.  Off-white diamonds absorb light, inhibiting brilliance.  You can best observe diamond color by placing the stone table-side-up on a flat white surface or grading trough, and examining it from different angles.  Next, place it table-side-down with the culet facing you, and examine it through the pavilion facets.

(14) Cut-

The cut of the stone has the greatest influence on a diamond's fire and brilliance,  A round, brilliant-cut diamond has 58 facets.  When well-proportioned, this shape best shows the stones's brilliance because it allows the most light to be reflected back to the eye of the observer.  Stones that appear lifeless or seem dark in the center are probably poorly cut.  When the angle relationship between the crown and pavilion facets is correct, rays of light entering the diamond strike the rear facets at an angle greater than the critical angle (24.5 degrees for a diamond) and reflect back to the eye of the observer.  If the stone is cut too deeply, the light strikes the rear facets at an angle less than the critical angle and the light is lost through the sides of the diamond.  If the stone cut is too shallow, the light passes through the diamond without being reflected back.

(15) Clarity-

Most diamonds contain internal stress fractures and minute traces of non-crystallized carbon.  These inclusions are usually not apparent to the naked eye but can be seen in loose stones under magnification.  "Perfect clarity" means that no inclusions are detected when the stone is examined under a 10X lens.  Inclusions absorb light, preventing it from being reflected back through the front of the stone.  Their effect on the diamond's value varies with the size, number and location.  An inclusion in the center, beneath the table, is more visible than one near the edge and may be mirrored by the facets, magnifying the dulling effect.

(16) Carat-

The term "carat" originates from the ancient practice of weighing diamonds against the seeds of the carob tree.  the system was eventually standardized with one carat fixed at 0,2 grams.  Each carat is sub -divided into 100 points, so a quarter-carat is 25 points of 0.25 carat.  Although the carat is a unit of weight, not size, the carat weight of a diamond has come to refer to particular sizes.  If properly cut, diamonds of the same weight should be about the same size.  These sizes don't apply to other gems, however, because their specific gravities are different from diamonds and from each other.

(17) Precious Stones: Emeralds Cubic Zirconia

Emeralds come from the South American country, Columbia.  Emeralds differs from others gems, as Type III gems, because they are the only major gemstone expected to have visible inclusions; in fact, any specimen without them is immediately suspect as a synthetic or an imitation.   The Emerald belongs to the beryl family and gets its green color from traces of chromium and vanadium.  Many emeralds are treated with an oil to enhance their color.   Clarity is measured using a jeweler’s loupe (a small magnifying glass used to view gemstones) under 10-power magnification. Because each emerald forms under its own, unique circumstances, each individual gemstone is comprised of a combination of trace minerals, which lend a precise color as well as unique identifying marks or inclusions.
  “Jardin” or “gardens” are natural inclusions you see in all the Emeralds, at naked eye or with magnification, this allow emeralds show the mystery and beauty of the most desire gemstone in the history. The wonderful gardens are the birthmark of emeralds that make differ of Natural Emeralds to synthetic emeralds. There is not two Emerald internal gardens that match.   The best clarity for emeralds is VVS or i1, minute inclusions to 10x and fine emeralds can start with SI1or i4 clarity scale.
Mohs Hardness: 7.5-8 /Refractive index:1.560-1602 /Specific Gravity: 2.68-2.78 /Treatment: Oiled

(18) Precious Stones: Rubies Cubic Zirconia

Rubies are a variety of corundum and is one of the worlds most valuable gemstones.  The ruby's color is due to a trace of chromic oxide: the amount of this substance determines the depth of the ruby color.  Because of the hardness and durability, rubies are an excellent choice for all types of jewelry.  r\Ruby is the birthstone for the month of July.  The earliest record for the mining of rubies goes back to more than 2,500 years ago in Sri Lanka. Historically, many believe that mystical powers lie within this intensely colored red gemstone. When inserted beneath the skin, the ancient Burmese believe that the stone generates a mystical force, which protects the wearer from accidents and attack. In the ancient world, many believed rubies to contain prophetic powers, enabling wearers to predict their future based on the color changes of their gemstones. The ancient Hindus enchanted by the color of rubies considered them to be "Ratnaraj" or the "King of Precious Stones".  The modern word ruby is derived from the ancient Latin term "Rubeus".Today, Burma is the world's largest provider of high quality rubies. Many consider Burmese rubies from the Mogok Valley to be the world's finest. Vietnam, Kenya, Tanzania and Sri Lanka are some of the other providers of this truly enchanting gemstone. Thailand, with large deposits near the Cambodian border, was previously the world's largest provider of rubies, but due to environmental regulations, the mining of gemstones has been greatly reduced. Rubies and sapphires are closely related, having corundum as their base mineral. The difference in color occurs because of the different trace minerals contained within each gemstone. Thai rubies tend to have a darker color and less intensity than Burmese rubies, which are known for their high quality and high price range; however, very fine rubies can be found in Thailand at very affordable prices. African rubies tend to have heavy inclusions, but beautiful stones with fine clarity can be found, usually in the higher price range.
Mohs Hardness: 9 /Refractive index:1.760-1.770 /Specific Gravity: 4 /Treatment: Usually Heat treated

(19) Precious Stones: Sapphires Cubic Zirconia

Sapphires are a corundum, a crystallized oxide of aluminum.  They contain traces of titanium and iron, which are what give sapphires their blue color.  If other mineral traces are also present, a sapphire may have a color other than blue, such as yellow, pink,, orange, violet or green. A corundum gem that is not red or blue is known as a "Fancy Sapphire" 
Sapphires have strong refraction, which favors the use of the same brilliant cut that is used on diamonds. Sapphires have a moderate dispersion. They do not have as strong a dispersion as diamonds, and thus they do not share the diamond’s “fire".   Rubies and Sapphires, both are corundum and are basically the same gem, except that rubies are always red and sapphires can be a variety of color.  Sapphires are mined mainly in Australia, Myanmar (Burma), Kashmir, Sri Lanka, Thailand, Vietnam, Afghanistan, Pakistan, and Cambodia. Some of the best sapphires come from Sri Lanka. Australian sapphires are deep blue to nearly black. Montana, USA, has metallic blue sapphires.   Many of the best blue sapphires come from Kashmir, but production has dropped off greatly due to political strife in that area. Kashmir sapphires do not change color under electric lights, while sapphires from other places take a navy blue tint under electric lights. Small, needlelike inclusions called rutile silk often deepen the blue and soften the Kashmir sapphires. Rutile silk often increases the quality of a gem, although it can sometimes cause the gem to lose brilliance, making them of little value.  Sapphires usually occur in crystals of twelve-sided prisms. Most sapphires have faults, and some have silky-looking internal patches.  It is believed that about ninety percent of sapphires and rubies are heat-treated to increase the quality of their color. This treatment is accepted as bona fide in the gem business, and it is unlikely the trend will change. Slight flaws are also sometimes burnt out of the gems.   A sapphire, especially a blue one, should first be worn only after trial. Even a perfect sapphire is sometimes unlucky and will cause trouble to the user. To test a blue sapphire one can wear the gem wrapped in a blue cloth bound around one’s arm for a week. One can also place it under his pillow for three nights. If there is any bad effect, the sapphire should be rejected.  Blue Sapphire (Neelam) Cornflower-colored sapphires are considered the most valuable. Blue sapphires without flaws, with evenly distributed color, that are well-cut and brilliant, are the best.
Mohs Hardness: 9 /Refractive index:1.760-1.770 /Specific Gravity: 4 /Treatment: Usually Heat treated

(20) GIA* Color Grading Scale

GIA* Color Grading Scale
Near Colorless
Faint Yellow
Very Light Yellow
Light Yellow
Fancy Yellow

(21) Semi-Precious Stones: Amethyst

(22) Semi-Precious Stones: Swiss Blue Topaz Swiss Blue Topaz

(23) Semi-Precious Stones: Garnet amethyst

(24) Semi-Precious Stones: Honey Citrine amethyst

(25) Semi-Precious Stones: Peridot peridot

(26) Synthetic Stones: Faux Diamonds - Cubic Zirconia Cubic Zirconia

(27) Freshwater Pearls

Freshwater and salt water pearls may sometimes look quite similar, but they come from different sources. Freshwater pearls form in various species of freshwater mussels, family Unionidae, which live in lakes, rivers, ponds and other bodies of fresh water. These freshwater pearl mussels occur not only in hotter climates, but also in colder more temperature areas such as Scotland (where they are totally protected by the law). see freshwater pearl mussell. However, most freshwater cultured pearls sold today com from China.

Back to top

Mark Ehrmann Jewelry Designs 1984-2011 ©    |    Contact