So this silver Durotriges coin had a bad case of ironoxide (rust) and copper oxide deposits on the reveres (and also a little bit on the observe). While copper oxide is relatively easy to remove using a weak acid solution, iron oxide is much harder to remove. In this case, I used a combination of mechanical (using a metal tool to remove the iron oxide layer) and chemical cleaning (weak citric acid in distilled water), with a total cleaning time of approx. 10 hours. The coin showed some porosity (perhaps someone else tried cleaning it before). In hand however, this is much less visible. The details however are a bit vague. A note regarding the images: the before was photographed in daylight, the after with artificial lighting in the evening. This enhances the porosity, which under magnification however (and in hand), did not increase. It is difficult to capture the character of the coin. Durotriges Celts, silver stater. Obv: head of apollo Rev: horse, pellets. Diameter 18 mm, weight 3.89 g Ref (not sure, any help appreciated) van Arsdell 1205-5
Nice job on the reverse .. cleaned up very nice. Too bad it has limited details due to wear but very interesting none the less.
