No visible mint means it was struck at the Philadelphia Mint. It is part of the clad coinage introduced in the mid-60s. It was graded by SGS as MS70, which denotes a perfect uncirculated condition. On the reverse the word QUARTER is resting on the bottom rim and a couple of the letters in AMERICA are setting on the eagles wing, a couple of the holes in the "As" on the reverse are almost filled in. $100 not a $1000