Cautions:
Avoid breathing the fumes and avoid skin contact. Nitric Acid, Hydrochloric Acid, and Aqua Regia are extremely poisonous and corrosive !
Since the testing procedure requires the use of dangerous acids, special care should be taken not to spill or allow acid to touch the skin.
If acid comes in contact with the skin, wash the affected area with a mild soap and water as quickly as possible.
NEVER POUR WATER INTO ACID. YOU MUST POUR ACID INTO WATER!!
You will need:
Nitric Acid (C.P.),
distilled water to mix the test solutions.
Potassium dichromate salts for making Schwerter's testing fluid.
Two acid bottles with ground glass stoppers and applicators
A Test stone
A graduated cylinder is recommended to measure the required proportions.
These items may be obtained from laboratory or chemical supply houses or local drug companies.
Mix 10 grams potassium dichromate salts with the ¾ oz. nitric acid plus ¼ oz. distilled water.
NEVER POUR WATER INTO ACID. YOU MUST POUR ACID INTO WATER!!
Testing Silver
Scratch the article with a file and apply a drop of Nitric Acid. If it turns green, it is plated. If a cloudy cream, it is sterling or better. (Some silver contains less than 90% fine silver).
Testing Base Metals with Schwerter Salts
File a notch in the test piece and apply a drop of Schwerter's Solution in the notch.
Observe the colour reaction.
Schwerter's solution indications
Brass - Dark Brown
Copper - Brown
Nickel - Blue
Palladium - None
Gold - None
- Silver Pure - Bright Red
- Silver .925 - Dark Red
- Silver .800 - Brown
- Silver .500 - Green
Lead - Yellow
Tin - Yellow
Buy a silver testing kit for £12.95
