informatives in english

About gold:

Click here for german version.



Break gold
Old gold
Dental gold
Gold price
Gold – fascination of the precious metal
Determining density of gold
The gold test for at home
The magnet balance
Winning back gold again

Purchase of gold

If you would like to sell your old valuable pieces of jewellery made of gold or other noble metals, you should trust only an expert.
Goldsmith master Andreas Stratmann suits you aside with his long-standing professional experience also for the purchase of gold topic. we will tell you the goldpreis for your jewels.
Trust a goldsmith master who was entrusted with the purchase of gold topic again and again in the context of change work, custom made jewels and fixing jewels about more than 30 years.

Break gold

As break gold become gold residues described, which arisen at repairs have and customers have been given to which again. Under this pieces of gold taken out in the context of ring stretching changes e.g., faulty and torn chain parts like faulty jewellery, rings get on without stones and so on.

Old gold

One understands by old gold the older pieces of jewellery which are not contemporary any more. Cases of pocket watches, so-called desperately poor tapes with coins, fasteners, pearl closer, old wedding rings belong to it, and anything eles. So there is meant herewith all jewellery which today nobody would like to wear anymore, because it is too much old-fashioned, defective or simply.At the company Goldschmiede Stratmann (goldsmiths Stratmann) we don´t like to use the name old gold on account of the negative character. Since, finally, you have as a customer not old gold, but precious metals, like platinum, gold and silver in which form also always may be given. The alloy price of old gold and break gold is a little bit behind the golden price, because the base metals must be separated first from the pure fine gold.

Dental gold

Differently than with jewellery – alloys there is a huge number of dental gold alloys. To work user-friendly, we make a distinction by the golden buying after dental gold – yellow and dental gold – grey/white. Dental gold – yellow: it concerns old yellow dental gold crowns and bridge parts, mostly of older date. Because earlier with higher fineness was worked, the gold price is a little higher for this as a rule than with grey dental gold. Dental gold, grey and white gold alloys: On this occasion, it concerns everybody grey to grey-yellowish dental gold crowns and bridge parts which are mostly of younger date, the so-called savings alloys with which already with less gold was worked. Because there are more and more often grey dental alloys which contain generally no more gold, we must determine with such dental gold alloys first the fineness with a X-ray fluorescence analysis.

X-Ray Analysis, english version.

dental gold, yellow coloured alloys: older crowns and bridge parts which are yellow clearly obviously are yellow classified.
dental gold alloys with white to grey – to yellowish colourings classified turn white. Dental gold alloys – whit we do not buy, nevertheless, you would like to sell dental gold – yellow ,multiply our topical gold price by the suitable gramme – weight for dental gold – yellow. You get the result cash paid.

Gold price

Profit from the gold price, in germany we call it goldpreis, which is permanently increasing. Trust only the expert for the purchase of gold topic.

Gold – fascination of the precious metal, why it is so heavy?

Above more than 6000 years pieces of jewellery are produced of gold, it is therefore the oldest precious metal used by human beeings. Because pure gold (fine gold) is too soft for the manufacture of jewellery, one went over later in addition, to melt it with other metals like silver and copper. At technical slang such mixtures of gold, silver and other precious metals calls golden alloys.
How rare gold is, it is illustrated figuratively by the fact that all gold which was promoted since people memory one day on the earth fills only one cube with an edge length of 20 metres. This sounds first after surely a little, one must think here, however, of the high density of gold. What does mean the word Density?
Pure gold, so fine gold, has a density of 19.3 grammes per cubic centimetre (g / cm ³). It is 19.3 times more heavy than water, because water has a density of 1 gramme per cubic centimetre (g / cm ³). Because to us does not say yet so much, we compare once by a car. A small car (like VW UP) weights aproximatley 1 tonn. Everybody knows, how big such a car is. The same amount of gold (fine gold) would fill a cube with an edge length of jut 37.28-cm edge length!
19.3 g / cm ³ corresponds 0.0193 kg / cm ³. How much cm ³ needs 1 tonne? We share 1. 000 kg by 0.0193 kg and receive a value from 51. 813.47 cm ³ which 1 tonne of pure gold needs. This listens a lot, but this says us still nothings about the size of the cube, the edge length must be still calculated. So we put the third root from 51. 813.47 and receive a value from 37.28-cm edge length.

Determining density of gold

One of the probably oldest non destructive genuineness check with objects of gold is the density regulation:

According to the Archimedean principle the volume and then the density has decided next to himself. One finds further information about the Archimedean principle topic under Wikipedia: „Archimedean principle“. (german)

The story of Archimedes to which has occurred in the bathtub as he can find out whether the crown of the king made of pure gold is or not is also described there.
The Archimedean principle means that a body displaces the quantity water, which corresponds its to volumes.
Accepted we have a ring of 19.3 grammes weighs and supposedly of gold should be, we can weigh the ring in water (what goes, however, only with hydrostatisc scale,  the ring may not lie on the ground at container inside the water). As a weight (of the ring, not of the impetus) we will get 18.3 g. To calculate the volume, we must draw off the weight in the water from the weight in the air and receive the value 1 cm ³. After the formula Density is divided like mass by the volume the ring would have a density of 19.3 g / cm ³ with which would be proved that it concerns with the ring pure gold.

Goldbarren Test auf Echtheit 1

Gold - Test am 20g Goldbarren

Wiegen des Auftriebs eines Goldbarren

Der 20g Goldbarren im Wasser

The gold test for at home:

1. : We weigh the 20 g  gold bar in the air as usual.
2.: We place the water glass at the scale and push the tare button, so that the balance indicates  0 gram again.
3.: We fasten the gold bar to a cord, hold it into the water glass and note the result of 1,03 gram, whereby it concerns the lift, which the gold bar in the water experiences, so round a volume.
4. : We calculate the specific weight after the formula Density is divided like mass by volume, so 20 partly by 1.03 there are immediately 19.4 grammes per cubic centimetre.
5. : We find out that pure gold has a density of 19.3 g / cm ³. The gold bar is real. The low divergence is because of inaccuracies when weighing out.

Unfortunately one cannot find out with this method whether the gold bar has a false core.

Of course we still need the specific weights of the different golden alloys (333, 585 him gold, etc. ) which can be defeated according to alloy composition (more silver or copper in proportion to the gold) are variations and that is why just in approximately named becomes:
999 (24 Karat)  = 19,3 g/cm³

900 (21 Karat)  = 17,5 g/cm³

750 (18 Karat)  = 15,1-15,8 g/cm³

585 (14 Karat)  = 13,1-13,6 g/cm³

375 (9 Karat)    = ca. 11,2  g/cm³

333 (8 Karat)    = 10,5-10,9 g/cm³
To the gold test for at home you can also have a look at the video. Action is here additionally yet demonstrated on an imaginary 585 gold ring:

Gold test for at home, video


Magnetwaage, magnetic scales

The magnet balance

With the magnet balance falsifications can be identified also without special experience very surely and without destruction. In particular so-called „Doubletten “, with which it concerns ingot or coins with a core from Wolfram or other materials, can be identified as those.
he high field strength of the neodymium magnet has a substantially higher penetration depth than conventional magnets, which makes a detection possible of paramagnetic or ferrousmagnetic inclusions in precious metals.
Fine gold and fine silver are not magnetic, they are pushed rather from a magnetic field. One will never get a negative value indicated.
Even paramagnetic materials such like wolfram (tungstens), molybdenum, and other one are pulled in into a magnetic field and recognized as falsification material, because the magnet takes weight off from the balance, which was set before at the measurement by the tara button to zero, now range indicates a negative value at the minus area.

magnet scales video- brass MagnetwaageVideoMessing

magnet scales video- gold MagnetwaageVideoGold

Winning back gold again

Gold schmelzen

Gold schmelzen, melting gold

One of the special qualities of gold is his indestructibility. Old gold can become recyclet again and again. Again and again, one can win back the refined gold contained in it, Gold. Special gold and silver departing institutions have specialized in this recycling process.

Know goldsmiths to reason Their training different to the gold alloys even for alloying and meltings.
However, the jewellery from donations or inheritances to which maybe still a personal respect exists he is not contemporary any more and does not correspond to own images and demands, can be altered according to individual images, or be incorporated in a new manufacture.

Goldsmiths can transform in this manner your old gold into new jewellery, makes to the joy.

Read moreover also on our Internet site the reports

„Gold, … We would have heard on grandpa!“ and Gold – The alloys in the jewellery areanach oben

Jewelery Goldsmiths Stratmann

You find further information about our goldsmiths company „Goldschmiede Stratmann“ under

We have established a „virtual workshop tour“ there for you which generally is very interesting.

Besides all gold works we offer:

-Gold platings

-Engravings of every kind: Hand engravings, machine-made engravings also CNC

-Precious stones take hold plus

-Mike welds finest weldings also directly next to sensitive objects

-Analyses, reports,

-Gold smithy courses, workshops

-Purchase of gold, noble metals and diamonds (we will tell you the goldpreis for your jewels promptley).

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