I used crowns to display how close grading is for the larger coins. All the above coins cover the weight range of 29 to 30.08 gms and for many collectors would be acceptable specimens. Hiding a 1 gramme loss on a 30 gramme coin is easy, its not so easy on lower weight coins where that 1 gramme can represent as much as 1/3 of the target weight on for example a sixpence.
Weight has allowed us to place the crowns in an order of preference if everything else is equal. So is a good First cut.
From here it it becomes very subjective. What might one encounter ? -
* Physical damage - holes, edge mount marks, scratches, surface staining, surface pot holes
* Surface Corrosion, partial or whole of coin
* Mis-shapen coins to the point where round appears square, many of the lower denominations were struck from irregular pieces of silver, cut down to weight.
* Off centre die positioning from the hand hammer process
* Uneven depth to image on the coin from partially worn dies, worn usually in the centre
* Displaced images from the use of cracked dies
* Cracked flans are often seen around the edges
* Uneven toning or even a recently cleaned coin
* Double striking where dies have been struck and displaced slightly between strikings
* The roundness of a coin is often dictated by the quality of the initial blank, round coins are usually more desirable
* The use of rusty dies which roughen the field areas of a coin
* Uneven wear caused either thru circulation or missing edge bead exposing the centre of the coin to uneven wear
* Previously bent coins used for love tokens which have since been straightened
These are the most common detractors which are taken into account during grading. They are reduced in severity for coins as one looks at the rarer coins as there is a very limited choice available, sometimes only one known specimen which is what it is. The term “for issue” in a descriptor which generally covers this area and periods when the quality of coins produced poor - anchor coinage, hammered Charles II restoration coinage or late Charles I coinage.
How far can detractors change a weight grade? Depending on number and the severity the effect on overall grade will vary but it is inevitably a reduction in grade.