White Gold

White gold or whitegold is a white alloy, which is composed of the two main precious metals: platinum and silver.
Its color is determined by the content of platinum and silver, and its jewelry can therefore be produced in several shades of white.

In order to meet the demand for the so-called "diamond white gold" with the white shade similar to 18k white gold, the pieces are alloyed with platinum and palladium, but not with silver.

White gold jewelery is much harder than yellow gold and has a very bright color.
If it is washed in soap water, it will remain bright, however, it will quickly tarnish and turn blackish when exposed to air.

White gold is a good alternative to other white jewelry metals such as platinum or palladium.
However, its cost is more than twice as high as that of yellow gold.

This is 24K gold alloyed with “white” base metals such as silver, palladium, nickel and sometimes zinc. The quantity of alloy added, will determine the karat rating of white gold and therefore, its final color. White gold is more durable than yellow gold, though it will still have a yellowish hue. In some cases a piece of jewelry will be coated in a platinum based metal, known as rhodium plating (see below) to give the appearance of being completely “white”.

Yellow gold

Yellow gold is one of the most popular choices in jewelry among men, but what exactly is it?

Somewhere between white gold and rose gold in color, yellow gold is a combination of two metals: gold (mostly) and copper.The presence of copper makes yellow gold a great alternative to white gold, which is also composed of gold, but usually has nickel added to it.

Not only does the presence of copper give yellow gold a more natural look, but it also makes it more affordable. The addition of copper makes yellow gold easier to work with, because it is less brittle than pure gold. It is softer than white gold and can be worked with tools made for softer metals.

The softness and malleability of yellow gold make it great for jewelry making projects like stamped designs, welded pieces and cold connections, which are difficult or impossible to create with white gold.

Rose gold

Rose Gold is actually pink gold. It was first used in Asia to make jewelry that was then imported back to Europe and sold as exotic jewelry. The reason why Rose gold is called rose gold is because it was a mixture of copper and gold with a reddish tint. Rose gold is different from red gold in that it has a much more copper content than red gold and is lighter in color. Rose gold is created through an electrolytic chemical plating process where the internal color that is desired is mixed with a solution containing copper ions. After this solution is applied to the metal, it undergoes an electrochemical reaction causing the copper ions to bind to the surface of the metal and change its color.

The most common way of making rose gold is by taking yellow gold, adding copper & palladium, and copper & nickel. The resulting product will naturally have some variation in its tone and color. The ratio of copper, palladium, and nickel will affect the resulting rose gold tone.

Platinum

Platinum is not a metal, but a group of close chemical compounds consisting of platinum metal and one or more non-metallic elements. In its pure form, platinum is extremely rare and valuable, but when it occurs as trace components in alloys, it is less costly. Pure platinum has a bluish metallic luster, but when an alloy containing platinum is formed with gold or copper the resulting metal has a reddish-yellow color.

Although Platinum is mainly used for its catalytic properties in chemical reactions, it is also effective as an electrical conductor and heatsink. It is also used for jewelry. Platinum is a malleable metal and has historically been popular for minting coins that are non-corrosive and have a long life span. Platinum is one of the least reactive metals. It does not react with oxygen or water at normal temperatures. It is also highly unreactive to most acids and bases.

Silver

Silver is a precious metal with the chemical symbol Ag and atomic number 47.A soft, white, lustrous transition metal, it possesses the highest electrical conductivity of any element and the highest thermal conductivity of any metal. The metal occurs naturally in its pure, free form (i.e., as unstabilized elemental silver), in minerals such as argentite and chlorargyrite, as a free salt called argentic acid, and in trace amounts in zinc ores and their smelters' dust.

Silver is a precious metal obtained from the mineral argentite, found primarily in Mexico, Peru and Bolivia. It has traditionally been used to make jewelry. However, its use in the manufacturing of consumer products has grown since the late 20th century. The price of silver can be affected by many factors, including changes in the supply and demand for jewelry, the industrial demand for silver, political uncertainty and events that impact supply or demand.

14k 

14k is the most popular alloy of gold used by jewelers and is often labeled as "gold-filled". Gold-filled is composed of a solid layer of karat gold bonded with heat and pressure to a base metal such as brass or nickel. This is true "gold" and not gold-plated. The weight of 14K gold filled is greater than solid 14K gold.

18k

18K is the purest form of gold, with a minimum of 750 parts per thousand. The most common karat grade found in fine jewelry, 18k is a traditionally handcrafted process used to mix gold with other metals, imparting toughness and durability.

18k is used to craft many modern and classic rings, earrings, necklaces and bracelets. Modern day 18k jewelry is often finished with a rhodium or gold plate in order to avoid tarnish, as well as for its white color. Some 18k pieces feature gray hues that match the color of sterling silver and platinum jewelry; these pieces are called gilt.