Quote from: 'Cooper S' pid='61102' dateline='1413693955'Are they just indents from something like a rock?
When you find something like this, there are a few questions to ask.
Firstly, how old is the coin, and what condition is it in? In the 12 years since this Outback 50ยข was minted, its pretty likely its had a fairly hard life.
Secondly, this type of effect could be a strikethrough or PMD, most likely acid, as stated. Learn to differentiate the two, as they're quite clearly different. A strikethrough, generally through a lump of gel-like grease, generally leaves a lumpy bottom to the crater, with sharp edges at the surface. They're usually quite deep, and usually limited to one or two instances on the coin. If the coin is new, the foreign material is usually still present.
As a strikethrough wears, the edges of the crater may wear down, but the bottom will still be intact. The crater often will intersect design features.
Acid damage however will generally be on the field only, and where it contacts design elements, will either undercut the raised surface, or eat it away, but without the sharp edge. The mark(s) will be quite shallow, and often have smaller pits in the bottom. There may be numerous marks, depending if the corrosion was deliberate or accidental.
Also, hard to describe exactly, but they just look different in the hand. The exposed metal is cleaner, shinier that the rest of the coin, especially if the damage is recent.
Strikethroughs are unique flaws, and IMO always worth keeping. PMD has no value, other than face, obviously, and any curiosity value as a reference or in the case of striking examples (some burnt coins are quite beautiful, but obviously PMD).
Hope this helps, and welcome back. :)
Hrm.. that's an awful lot of 'generally's'... I blame my current blindness. Ah well.