Gold has an extraordinary heritage with unique qualities. As an enduring element found naturally in a distinct yellow color, gold is resistant to rust, tarnish, and corrosion. Although gold is very strong, it’s also the most malleable of all precious metals.
Pure gold is too soft for everyday wear, so it is alloyed with a mixture of metals like silver, copper, nickel, and zinc to give it strength and durability.
The colour of gold is determined by two factors:
- The type of metal alloys included
- The percentage of each metal alloy
Natural gold and colour-saturated alloys are what give yellow gold Jewellery its rich shine. The alloys most commonly used, are copper with a red hue, and silver featuring a green hue. An expert mixture of copper, silver and pure gold gives this precious metal its signature warmth.
A silvery white character is what makes White gold Jewellery so appealing. To make the gold white, it is combined with metal alloys that are white in nature and plated with an extremely hard element called rhodium. Although strong, rhodium may wear away over time. Replating is a simple process that can be done to restore whiteness to your Jewellery.
The beautiful pink hue of rose gold Jewellery is created by using a copper alloy. Again, the overall percentages of metal alloys are the same for rose gold as it is for yellow or white, there is just a different mixture in what alloys are used.
Since gold is a natural element, it is affected by harsh chemicals such as chlorine or other cleaning products. We recommend that you remove your Jewellery when using chemicals to reduce daily abrasions and prolong the luster. To clean gold jewellery, use a solution of warm water and detergent-free soap with a soft-bristled brush. When not worn, store your gold pieces in soft cloth bags or the original box to protect them from the elements of daily exposure.
What are the different types of gold in jewellery?
When you are buying gold jewellery, you often get to choose between different types of gold colours, gold carats, and gold plating options. What do all those things mean, and is there a big difference between the different gold types?
Gold jewellery is not pure gold. It is an alloy; a mixture of metals. Gold jewellery can be alloyed with silver, copper, zinc, palladium, and nickel to create different gold colours. The most common gold colours are: yellow, white, rose, and green.
Yellow gold is made by mixing pure gold with silver, copper, and zinc. It is the purest colour, the most hypo-allergenic, and requires the least maintenance of all the gold colours.
White gold is made of gold and platinum (or palladium). White gold can also be made of gold, palladium, nickel and zinc. White gold is more durable and scratch-resistant than yellow gold. It is also more affordable than both yellow gold and platinum.
Rose gold (or pink gold) is alloyed with gold, copper, and silver. Rose gold is more affordable than the other gold colours because it uses the inexpensive copper for its rose colour. Due to its copper content, rose gold is more durable than yellow or white gold.
PLATINUM ALLOYS – Recommended Platinum Alloys for Good Manufacturing Practise
Uses for Platinum Alloys
Pt950/Rethenium (hardness 130HV) – due to high hardness the working properties, this alloy is preferred as a universal alloy. It can be cast, machined and used for hand fabrication
Pt951/Cobalt (hardness 135HV) – due to its high hardness and the line grain, this alloy is preferred as a casting alloy. Because of its strength it is also used for fine wire in chain making.
FINENESS OF GOLD – Percentage of Gold in Alloy
WEIGHT CONVERSION BETWEEN METALS
HOW TO USE THIS TABLE
You have a 9ct ring that weighs 8 grams. What will it weigh in 18 ct?
Along the horizontal row marked “9 ct” and in vertical column under the heading “18 ct” we find the factor 1.34
8 grams x 1.34 – 10.72 grams in 18 ct
WEDDING BAND WEIGHT ESTIMATION – A Formula to Estimate the Weight of Rings Various Metals and Sizes
1ct diamond = 0.2 grams
1 gram = 5 carats
1 carat = 4 grainers
1 inch = 2.54 centimetres
1 ounce (oz) = 31.1035 grams
1 Kilogram (kg) = 32.1507 ounces
1 centimetre = 0.394 inches
METAL MELTING POINTS
Gold 9 ct
800 – 960
Gold – 24 ct
Gold 14 ct
850 – 920
Gold 18 ct
990 – 1030