; (13) Plymouth 400, Inc. will lead, support, and facilitate legislative and marketing efforts for a commemorative coin series, United States postage stamps, and related activities for the Plymouth 400th anniversary observances and commemorations in 2020; (14) a commemorative coin series will bring national and international attention to the lasting legacy of Plymouth Colony, the indigenous Wampanoag Tribes, and the Pilgrim settlers; and (15) the proceeds from a surcharge on the sale of such commemorative coins will assist the financing of a suitable national observance in 2020 and 2021 of the 400th anniversary of the Pilgrim landing and historic events, including the signing of the Mayflower Compact, the first shared harvest, interaction with the indigenous Wampanoag people, and other significant events of the period. 3. Coin specifications (a) Denominations The Secretary of the Treasury (hereinafter in this Act referred to as the Secretary ) shall mint and issue the following coins: (1) $5 gold coins Not more than 100,000 $5 coins, which shall— (A) weigh 8.359 grams; (B) have diameter of 0.85 inches; and (C) contain 90 percent gold and 10 percent alloy. (2) $1 silver coins Not more than 500,000 $1 coins, which shall— (A) weigh 26.73 grams; (B) have a diameter of 1.500 inches; and (C) contain not less than 90 percent silver. (3) Half-dollar clad coins Not more than 750,000 half-dollar coins which shall— (A) weigh 11.34 grams; (B) have a diameter of 1.205 inches