Making Moderns column from July 11, 2016, Weekly issue of Coin World:

The most logical way to collect the America the Beautiful 5-ounce silver quarter dollars is to buy one of each issue.

As with most U.S. Mint products, the coin is made in more than one version. One is a bullion version without Mint mark. The other has a special finish, called Uncirculated by the Mint, that is imposed after striking; this coin has a P Mint mark and is expressly for collectors.

The bullion coin receives no post-striking treatment. Early in the series, from 2010 into 2011, the surface of these coins was most often slightly satin in appearance.

Occasionally, bullion coins with mirrored surfaces were seen. Such coins are called “prooflike” by grading services when a coin has a mirror-like surface that reflects objects from a distance of 2 inches. The term “Deep Prooflike” is used for coins with no cartwheel luster and that clearly reflect objects from 4 inches or more.

For coins in the bullion series since late-2011, most of the coins are at least prooflike when issued. 

When ejected from dies, these coins slide down a chute and are packaged in tubes of 10 coins. As a result, they always show some abrasion. The bullion coin is often found in the lofty Mint State 69 grade, but does not exist in MS-70 grade, assigned to a coin with no post-production imperfections at 5x magnification (NGC’s definition). 

The most valuable bullion coins to collectors are therefore those assigned the grade MS-69 Deep Prooflike. Some issues like the 2010 Yellowstone and Grand Canyon coins can be difficult to locate at this grade level. Deep Prooflike pieces can command significant premiums for scarce issues. 

The majority of collectors building sets are drawn to the Uncirculated versions, not the bullion coins. The grading services have certified about 30 percent to 50 percent more of these than of the bullion coins.

After striking, the Uncirculated coins are “vapor blasted.” They are bombarded with ceramic beads, giving their surfaces a flat, matte texture. Then, they are placed in capsules by state-of-the-art packaging machines using soft tips and vacuum suction. Delicately handled, they are readily available in the 70-grade.

The grading services denote the Uncirculated coins as SP for Specimen instead of MS for Mint State. This is done in consideration of the special handling and surface finish these coins receive, and how different they look from the bullion version. Thus the highest grade for these coins is SP-70 on the label.