This one-year mint mark type was used only in 1952. It is believed that the corners of the serifs were created too sharply, which caused weakness in the punch that resulted in a break that became quite noticeable before the punch was retired. This same fature (the sharp serifs) also lent to a number of 1952 Denver dies cracking in and around the date (chiefly the 9) toward and connecting to the upper serif (usually) of the mint mark.
Its shape appears to be squatty, smashed. It is shorter than the width would indicate. Most are quite sharp in appearance because of the limited use of the punch. This results in a large number of rather minor repunched mint marks with split serifs.
