Complex sentence: Some 150,000 of the authorized mintage of 300,000 coins were struck in August 1925 in San Francisco; they were offered for sale the following month, but nearly half went unsold, and were later melted.
Split into simpler sentences: Some 150,000 of the authorized mintage of 300,000 coins were struck in August 1925 in San Francisco. They were offered for sale the following month, but nearly half went unsold, and were later melted.