Stop Button

<svg
    xmlns="http://www.w3.org/2000/svg"
    width="512"
    height="512"
    viewBox="0 0 64 64"
>
    <linearGradient
        id="a"
        x1="3.5"
        x2="60.5"
        y1="31.926"
        y2="31.926"
        gradientUnits="userSpaceOnUse"
    >
        <stop offset="0" stop-color="#c0392b" />
        <stop offset="1" stop-color="#8e44ad" />
    </linearGradient>
    <path
        fill="url(#a)"
        d="M32 3.5A28.539 28.539 0 0 0 3.5 32c1.573 37.808 55.433 37.797 57 0A28.539 28.539 0 0 0 32 3.5zM45.5 44a1.498 1.498 0 0 1-1.5 1.5H20a1.498 1.498 0 0 1-1.5-1.5V20a1.498 1.498 0 0 1 1.5-1.5h24a1.498 1.498 0 0 1 1.5 1.5z"
    />
</svg>