We often come across hearing numbers like 375, 585 and 750 associated with solid gold. Such numbers are also found in the case of sterling silver as well. But what does these numbers even mean?
In this article we will explain what is the meaning of 375, 585 and 750 in solid gold and why are they even used.
What is 375, 585 and 750 in Gold
All of these numbers are used to explain the purity level of solid gold in terms of percentage. We also use similar set of symbolization in unit system of “karats”. So, we can say that both of these systems (percentage and karats) are used to tell the purity level of gold.
What is 375 Gold
375 gold contains 37.5% of its composition made up of pure gold while the rest of 62.5% is of any other metal such as copper, nickel etc.
It is an equivalent to 9k or 9 karats in karat system where purity level is a measure of how many parts are of pure gold out of 24.
Karat system —> Percentage system
9K Gold = (4.167 * 9) = 37.5% Pure Gold or 375
What is 585 Gold
585 gold refers to a gold containing 58.5% of composition consisting of gold and 41.5% of other metals.
This gold type is equivalent to 14k or 14 karat of gold. Generally 585 gold is the most widely used purity level due to its optimum balance of hardness and shine.
Karat system —> Percentage system
14K Gold = (4.167 * 14) = 58.5% Pure Gold or 585
What is 750 Gold
750 gold contains 75.0% of gold content with 25% of other metals.
This type of gold is an equivalent of 18k in karat system.
Karat system —> Percentage system
18K Gold = (4.167 * 18) = 75.0% Pure Gold or 750
Why Can’t we have pure Gold Jewelry
Gold is a soft and malleable metal which can change its shape on smallest of forces. This makes it really impossible to be dealt with in terms of jewelry making. Jewelry often has complex designs where jeweler are needed to fit in small stones and make definite angles.
Under such circumstances, a metal being used for this purpose should be hard enough to hold stones and its shape. Unfortunately pure gold metal is unable to do it. That’s why we mix it with other metals to make different compositions like rose gold, yellow gold, white gold etc. The whole purpose behind it is to make it hard enough to fulfill the checklist. In this way, different purity levels of gold exist. The more hardness you want to get, lesser the gold you will put in.
Carat vs Karat
Some people might get confused between these two words i.e. carat and karat. It must be clear that both of these unit systems have different usage and meaning.
Karat
Karat is used to symbolize the purity level of gold whether it is in solid gold or gold plating. It is always measured out of 24 karats. Common karats are:
9k or 9 karats: 9 of the 24 parts is gold.
14k or 14 karats: 14 of the 24 parts is gold.
18k or 18 karats: 18 of the 24 parts is gold
Carat
Carat is used to tell the size of a diamond of a gemstone. Word “carat” is used next to the size of the gemstone for determining. For example, 2 carat diamond or 1 carat diamond.
Properties of 375 gold vs 585 gold vs 750 Gold
Properties of a gold type greatly depend on the purity level of gold. Here is a comparison of different gold purity levels among each other.
Appearance
When it comes to appearances of different gold alloys, a certain rule is followed. Greater the purity level, more yellowish the alloy will be and vice versa.
By this rule, 750 gold will have the closest appearance to pure gold among these three as it the greatest amount of gold in it. Similarly 375 will have the weakest yellow appearance and 585 gold lying in between these two.
Hardness
The same rule of appearance is also applied here but oppositely. Lowest the purity level of a gold alloy is, more hard it will be.
We all know that gold is a soft metal and is needed to be mixed with other metals to make it harder for jewelry making. The more you add metals like copper, nickel etc. the hard it gets. Harder alloys are easier to make complex customizable designs and do gold plating as well. But it does not mean that you have to compromise on purity.
There is a need to find an optimum balance in between purity and hardness so one do not have to compromise on any of the aspect. If you’re one who want maximum durability with customized designs, 14k or 585 is for you. Otherwise 750 gold is a good choice overall.
Durability
Softer gold alloy such 750 can be scratched and damaged more easily than 585 or 375. Harder gold alloys show better resistance towards dents and scuffs as well. So, it is better to get jewelry made of 375 gold if durability is a big concern.
585 gold is more prone to scratches and damages compared to 375 where 750 gold comes at the last.
Cost
Mixing of gold with other cheaper metals has another benefit. It brings the overall cost down. So, lower the purity level of a gold alloy is, cheaper it will be.
You can expect to pay far less for 375 gold compared to 750 gold as it contains higher percentage of cheaper metals like copper, nickel etc. As we move from 375 gold to 750 gold, gold content increases and so as the price.
Shelf Life
Shelf life of a gold jewelry is never a big concern. Regardless of their purity level, gold jewelries remain in useable condition for at least 30 to 50 years or may be more if proper care is taken care of. Tasks like regular cleaning, proper storing and saving from damages will always end your jewelry with a longer shelf life.
Maintenance and Care
Maintenance is another important aspect of owning gold jewelry. Gold alloys with lower purity are usually considered more prone to tarnishing where alloy can change its color due to higher copper content. For this, high maintenance and care is required including regular cleaning and using tarnishing prevention chemicals in case of any tarnishing signs.
585 and 750 on the other side require less maintenance as with more purity, chances of tarnishing drastically decrease. One can expect to do only monthly cleaning stuff.
Investment Value
As far as these three types of gold are concerned for investment purpose, 750 gold stand out on the top. The main reason behind it is having greater gold content than others. Usually gold prices are more stable and offering better returns than copper, nickel or other metals. This brings a sense of stability in terms of investment.
Similar goes with the resale value of the jewelry. Jewelries made of 375 gold are going to depreciated much faster than higher purity types. Apart from this you can expect an easier and smoother process of selling with 750 or 585 than 375 gold.
Please note that jewelry is never to be taken as an investment tool.
What to Choose?
Before deciding first a buyer has to make it clear what properties they want to have in their jewelry. If you’re one who is looking for a cheaper gold alloy and can do compromise on appearance, 375 might be a good option for you. People looking for a low maintenance demanding alloy can definitely go with 750 gold but it might cost more money. If you want to remain in between these two, 585 is the best option to have.
Conclusion
375, 585 and 750 are different purity levels of gold alloys used in gold jewelry making. All of these alloys contain different properties in terms of appearance, durability, maintenance required and cost. It all ends up on one’s personal needs and choices that what they choose. But before buying any jewelry made up of these alloys, make sure to have all the necessary information in making an informed decision.