The density of gold is one of the unique physical characteristics of this metal. Since it is soft, other metals are added to it for practical use to improve its processing properties.
In jewelry, as we know, precious metal alloys are used in different proportions. The content of pure noble metal in the alloy is measured in thousandths: the 585th sample is an alloy with a pure gold content of 585 parts out of 1000. The corresponding indicator is stamped on the product. Accordingly, with the addition of other metals, the density of gold, that is, its alloy, changes. Based on this indicator, at the places of receipt of gold products, their authenticity and compliance with the declared sample are determined.
Characteristics of gold
Precious gold is a heavy metal. Its density in its pure form is 19,621 kg/m³. To perceive the dry fact as vividly as possible, imagine a small ball of pure metal with a diameter of 46 mm. Its mass will be equal to 1 kilogram.
The high density of gold is also used in its mining: it is thanks to it that nuggets and sand can be sifted from rocks by washing.
Density of gold inpure form (the one that is considered to be 999, the 99th test) 19.3 g/cm3. Native, it has a slightly lower density: 18-18.5 g/cm3. In alloys of different samples, this indicator is different. We will talk about them further.
Density of gold alloys
As we know from the school course, the density of a material is a physical property, defined as the mass of a taken unit of volume. It is measured through the ratio of body weight and size.
To obtain alloys suitable for use in jewelry production, gold is mixed with copper, silver, nickel, platinum, palladium and other metals, both noble and not. Let's move on to data on the density of gold alloys of different samples.
The most popular, affordable and great to work with is 585 proof. The density of gold 585th test is 12.5-14 g/cm3. The same frames are determined by the 583rd sample (Soviet sample).
For coin assays, 900th and 917th, the indicators are, respectively, 17, 10-17, 24 g/cm3 and 17, 34-17, 83g/cm3.
Also common assay in jewelry, the 750th has a density of 14.5-17.5 g/cm3.
The density of base gold, 375-carat, - 11, 54-11, 56 g/cm3.
And, finally, let's remember another noble metal - silver. It is significantly lighter than gold, and the density of silver alloys is also lower.
Thus, the density of the most common 925 alloy in products is 10.36 g/cm3. The second most used, 875th test, - 10.28 g/cm3.
The density of gold and silver is an important indicator that helps to determine the content of pure noble metal in an alloy using various methods. We will talk about one of them, available, next.
Hydrostatic method: we determine the sample of the precious alloy
In institutions specializing in the acceptance of gold products, many different methods are used to determine and confirm the sample of the brought gold. Based on the knowledge that gold is a heavy metal with a high density, the hydrostatic method was introduced.
It is based on determining the difference in weight when measured outdoors, under normal conditions, and in a liquid with a certain known density.
Let's make a reservation right away: this method of checking gold is suitable only for integral products, without stones and other inserts from other materials. It is also impossible to obtain adequate data on hollow products consisting of many moving parts.
To carry out hydrostatic weighing of a gold item, you will need a jewelry scale, a measuring cup (or any other transparent one), a fishing line or a thin thread. Distilled water is usually used as a liquid of known density. First, the gold product is weighed in the usual way, the data is recorded. Then a glass of water, more than half filled, is placed on the scales, the scales are reset to zero (the scales must have a function to zero the tare weight). Our golden productsuspended on a fishing line, falls into the water completely, while not touching the bottom and walls of the glass. The scale data is also fixed.
For density analysis, it is better to use a hydrostatic calculator, since manual calculations will take much longer and are not as accurate.
Conclusions
So, in our article we examined the density of gold - a precious metal that each of us has encountered and will encounter in life. The data can be summarized as follows: the density of the most popular gold sample, the 585th, is 12.5-14 g/cm3, for other alloys it is smaller or larger, respectively.
The density of the gold alloy can determine the sample, which is an indicator of the content of pure gold in the alloy. These methods are used in the gold acceptance establishments.
We hope that our article was informative and gave you a few exciting minutes. Let only real high-grade gold be in your jewelry box!
