Gold Testing - GOLDANALYTIX 06-03-00015 Benutzerhandbuch

Abrasion on the stone
It is important for the testing do draw a clear line on the
touchstone. This can be done by placing the touchstone
on a plane surface while holding the stone with one hand.
With the other hand you have to press the sample on the
surface of the touchstone and rub it on the surface until
you have obtained a 3 cm long and 3 to 5 mm thick
abrasion.
Touchstone maintenance
For proper touchstone maintenance use the platinum test
acid in order to remove rests of rare metals (the platinum
test acid is the strongest acid and dissolves all other rare
metals). Use a common fine sand paper (1000 grading) in
order to sharpen the touchstone surface.

6. Gold testing

The test acids are adjusted in a way that all lower gold
alloys than the corresponding test acids are dissolved.
This means that a 333 gold alloy can´t be dissolved from
a 333 but from a 585 gold test acid. The speed of the
reaction depends on the temperature. At high
temperatures (≈ 30 °C), the testing liquids will work faster
than at low temperatures (< 20 °C).
Application
Draw a line on the test stone and cover it with the
weakest test acid (8 carats). Avoid rubbing the abrasion
mechanically. Wait for 30 seconds and follow the reaction.
If the abrasion disappears, the alloy is lower than 8 carat
gold. If the abraison does not disappear, use the next
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