1820 Capped Bust Half Dollar. O-105. Rarity-1. Square Base Knob 2, Large Date. AU-58 (PCGS). This desirable early date Capped Bust half dollar retains much of the original frosty to semi-prooflike finish imparted by the dies. It is generally brilliant, but with pretty iridescent toning in cobalt blue and champagne-pink at the peripheries. Sharply defined and visually appealing. PCGS# 6122.