The first few hundred coins struck from a new (or newly polished) die will usually exhibit some degree of mirror, or prooflike (abbreviated as "P-L') surface. The degree of prooflike surface may be noted in the grade description. (For example: MS-65, Prooflike ... MS-65, deep mirror prooflike.)
The degrees of P-L surface may best be enumerated in order of intensity, from least to most, as follows:
1. Satin-like (or satin surfaces)
4. Deep mirror prooflike
Deep mirror prooflike (D.M.P.L. or D.P.L., depending on the grading service you use) coins have fields that are nearly devoid of any cartwheel lustre. In addition, the term "cameo" is sometimes used to denote a P-L or proof coin with exceptional contrast. A cameo coin should have mirror fields, and the devices should display mint frost or "cartwheel" with little or no mirror-like reflective qualities.
Use the gauge on this page to grade the degree of prooflikeness on any Morgan silver dollar. Lay the coin by its edge on the red line, at a 90 degree angle (i.e, perpendicular) to the page. Place the page approximately 18 inches beneath a 60 watt incandescent lamp. Look at the coin from a 45 degree angle, approximately 12 inches away. The highest prooflike grade that a person with normal eyesight can clearly read within the coin's surface is the prooflike grade which applies to that coin.
NOTE: If the coin is toned, it may be somewhat difficult to see through the toning. Therefore, at first, it is best to use the gauge only with untoned coins. Eventually, you will be able to grade the "prooflikeness" of most toned and untoned coins without using the gauge.
(You might want to print this page out to administer the test more effectively.)