Gold is shining yellow metal. It has high plasticity and brightness, these characters determine its high value in jewelry industry and is most commonly used metal.
Karat is measure for gold containment in piece of jewelry and is part of metric system. Most commonly used ones are, 14 k, 18 k and 24 k. More karats mean more gold containment in jewelry. Today gold containment in jewelry is measured in two metric and karat systems. correlation between this two systems looks like this: 333 in metric systems is equal to 8 karat, 375 - 9; 583/585 - 14; 750 - 18; 900 - 21; 916 - 22; 958 - 23; 999 - 24.
Carat is term for measurement of stones weight. 1 carat is equivalent of 0,2 grams. All stones are measured in this system except for pearls which is measured in grans equivalent of 0,25 carat.
Jewelry pieces made from gold may vary by design, karat, color and weight. Most commonly used colors for gold is yellow, white and red. Rarely we can see green, pink or any other colors. Color of gold depends on other minerals contained in metal, by changing minerals we can get different colored gold.
Diamond is most durable mineral in world. Compared to corundums its is 100 times durable. It is not by chance that these stones are called kings of stones. According to legends old Greeks called stone "Adamas" meaning indestructible, this word became origin of word diamond. Another legend says that words etymology comes from old Arabic language.
Diamonds value is determined by 4C method. 4C stands for: Cut, color, clarity and carat. Cut is method used to augment diamonds brightness by cutting its edges. These edges determine how good final stone will be. Carat is measurement for stone, value of stone is connected to its weight. Clarity of stone means how much light can it reflect. More clear stone reflects more light making it more valuable.