Category: EDUCATION

Traditional Wedding Anniversary Stones:

About Gold
Pure gold (fine gold) is softer than pure silver but harder than tin. Its beauty and luster are unmatched by any alloyed golds. The extreme malleability, ductility, and softness of pure gold make it practically useless for jewelry applications.

Alloying elements (other metals) are added to gold to increase the toughness and hardness of the gold alloy. While almost any metal can be alloyed (melted) with gold, only certain metals will not dramatically change the color or make the metal brittle. The addition of indium, for instance, turns gold purple and gives gold alloy the workability of glass.

Over time, certain percentages of gold have become legally recognized “karats.” The karat indicates the amount of gold as a percentage of the total, i.e. 24 karat is 100 percent gold. Thus 14 karat is 14/24 gold or 58.33 percent gold. Gold standards vary around the world. In the United States, 24, 22, 18, 14, and 10 karat gold are the only karats allowed to be sold as karated gold.

In karated gold, there is a known proportion of metals in the non-gold percentage. These metals provide the various colors and hardness of karated golds.

Typical alloying elements and their color effect are:

• Copper Reddening
• Silver Greening
• Zinc Bleaching
• Nickel Whitening
• Palladium Whitening

Examples of the compositions of different colors are

• Yellow: Gold, copper, silver, zinc
• White: Gold, copper, nickel (or palladium), zinc
• Red: Gold, copper
• Green: Gold, silver

Adjusting the proportions of base metals (non-precious metals) provides the array of colors on the market. They also enhance properties such as castability, grain size, hardness, corrosion resistance, workability, ultimate strength, and ductility. These additions can dramatically change the properties of the karated gold for better or worse.

Knowing how the additions will affect the karated gold greatly enhances the possibility of a superior final product. In deep drawing of metals, it is important to have a metal which will elongate or stretch a great deal before fracturing, thus high ductility. The requirement for an earring post would be a high tensile strength (a great deal of force needed to get the material to permanently deform or bend). It is
imperative to select the proper karated composition for the desired application.

PLATINUM VS. WHITE GOLD
Platinum and white gold are two very different metals. The biggest differences between platinum and white gold are that platinum is a naturally white metal, and is more dense and durable. The difference in cost is primarily due to platinum’s rarity and higher level of purity in platinum jewelry. When comparing costs, keep in mind the maintenance required for white gold over a lifetime, such as rhodium plating to
keep it white and reshanking and retipping the prongs. Platinum may be a higher investment initially, but its enduring nature makes it the best value in the long run.

Platinum Technical:
Platinum Alloys

• Pt950/Ruthenium (Ru) is the best choice for multipurpose use. It is ideal for machining and fabrication. Casting will deliver good results.
• Pt950/Cobalt (Co) has a very fine grain and is ideal for casting. It is slightly Ferro-magnetic and oxidizes at about 1000˚C. The oxidation can be easily removed.
• 90/10 Platinum/Iridium (Pt/Ir) is a comprehensive platinum alloy. It can be used for all applications, but is best suited for fabrication.
• 95/5 Platinum/Iridium (Pt/Ir) is a fabrication alloy. It has high malleability and work-hardens rapidly. It is great for die striking, but it is not well suited for casting
  because of its low hardness.
• Pt950 heat-treatable alloys are ideal when spring action is needed or a harder product is desired. The hardening feature gives these all oys great flexibility

Color Grade:
With the exception of fancy-colored diamonds, the most valuable diamonds are those with the least color. Although many people think of gem quality diamonds as colorless, completely colorless diamonds are very rare.
The diamond color scale ranges from D (colorless) to Z (light yellow or brown).

A diamond’s color is determined by a manual process of comparing the diamond to a master set. Each letter grade represents a range of color and is a measurement of how noticeable a color is. When diamonds are formed with traces of other minerals, rare and beautiful colors can result. These “fancy” colors range from blue and brilliant yellow to red, brown, pale green, pink, and violet. Because of their rarity, colored diamonds are highly desirable and typically more valuable.

Clarity:
A term used to describe the absence or presence of internal or external flaws in a gemstone.

In-depth description:
Tiny surface blemishes or internal inclusions, even those seen only under magnification, can alter the brilliance of the diamond and thus affect its value. Clarity levels begin with flawless (FL, IF), followed by very, very slight (VVS1, VVS2), very slight (VS1, VS2), slightly included (SI1, SI2), and included (I1, I2, and I3)

Cut:
While cut does include shape, in terms of the 4 Cs it refers to the proportions of the cut. A diamond’s cut grade is an objective measure of a diamond’s light performance, or the amount of sparkle a diamond has.

A diamond’s overall proportions, as well as the size and position of its facets, make up the cut. The consistency and balance of these can greatly affect how the stone captures light and reflects it back to the eye. When a diamond is cut with the proper proportions, light enters the diamond and is returned through the top of the diamond. If a diamond is too shallow, light will escape from the bottom of the stone. If it is cut too deep, light will escape out the sides.

Studies have been conducted to find the optimum proportions of a diamond’s cut so that it has the greatest amount of sparkle. If its cut falls within these parameters, it is considered an ideal cut. Diamonds with fine proportions, symmetry and polish optimize their interaction with light and have increased brilliance, dispersion, and s cintillation.

Carat:
Carat refers to a diamond’s weight. One carat, the traditional unit of measurement for diamonds, is approximately 0.2 grams (200 milligrams).
You may also hear the weight of a diamond referred to in points. One carat is equivalent to 100 points, so a 75-point diamond is equal to 0.75 carats. Because they are rare, larger diamonds have greater value per carat, so the price of a diamond rises exponentially to its size.

• 1 carat = 31⁄16 grains Troy
• 1 carat = .007 oz. Avoir
• 1 carat = 1⁄5 gram

The carat is further divided into points for simple measurement:

• 1 carat = 100 points
• 1⁄2 carat = 50 points
• 1⁄4 carat = 25 points
• 1⁄8 carat = 12 1⁄2 points