The First Curved Coin from the United States Mint is a baseball hall of fame commemorative coin
The specs for the Gold and Silver are reasonable, but the Half-Dollar is only copper and nickel.
Specifications
$5 Gold
Weight: 8.359 grams nominal
Composition: 90% gold, 10% alloy
Mintage Limit: 50,000 across all product options
Height of Dome: 0.085 inches
$1 Silver
Weight: 26.73 grams nominal
Composition: 90% silver, 10% copper
Mintage Limit: 400,000 across all product options
Height of Dome: 0.150 inches
Half-Dollar Clad
Weight: 11.34 grams nominal
Composition: 92% copper, 8% nickel
Mintage Limit: 750,000 across all product options
Height of Dome: 0.058 inches