Testing about precious metals with acids

Hi friends , my name is Denis A. Mesa Borroto, I am a medical doctor
(Urologist) and Jeweler from Cuba. I need on how to
prepare de acids for test precious metals like gold (10k,14k, 18k,
22k), silver, platinum and paladium. I need the exact proportions of
every components for prepare the acids by myself. Because there is
not any place for by the kit in my country (Cuba). Have a nice St.
Valentine’s day. Denis.

Hello Denis, I have copied some of palonso’s text for you, it should
give you a start.

Martin Niemeijer.

concentration for 333 kt gold: 2 parts nitric acid to 3 parts water
(distilled water)

concentration for 585 kt gold: pure concentrated nitric acid.

concentration for 750 kt gold: add a little amount of hydrochloric
acid to the concentrated nitric acid.

concetration for silver: 1 part of nitric acid to 3 parts of
hydrochloric acid (agua regia). This solution creates a white
deposite of silverchloride which turn into a dark violet color
depending on the amount of silver in your metalstrike used by a
touchstone procedure.If the metal doesn’t contain any silver,the
metalstrike stay’s gray or dissapears after a while.

I’m sure that people have other recipes but this is what I know using
the chemicals you mentioned in your e-mail.

Be carefull and use a well ventilated room.Add acid to water
(slowly!!)and not the other way around.Add acids together slowly and
check out the reaction.Work in a area where you can easely provide
yourself with clear water in case someting happends.have somebody
(adult!!)as a backup if something should happen to you and brief the
person in case of.Definetly keep it out of reach for children.
If,however,something should happen,prepare next solutions before you
start working with the chemicals.Make a mixture of calcium and water
to drink or a lot of milk if some of the acid mixture is swallowed by
accident.In addition swallow chrunced ice cubes after drinking the
milk and contact a doctor as soon as possible.Do not try to vomit
since this causes double trouble.Wash off immediatly spilled acid on
your skin with clear cold water and alcalic soap.Wear eye goggles and
gloves even if you’re shure that you’re save and chose good
ones.Don’t drink,eat or smoke during the procedure.If you work inside
take the person immediatly outside to breath fresh air.After you
completed your work,take the time to wash yourself befor you
eat,drink,smoke or shake hands with someone. It all sounds a little
bit tomuch,but believe me I have seen it and it wasn’t plesant to see
and I’m not a softy.Precautions are saving your and other peoples
live.

Regards Pedro
Palonso@t-online.de