test.svg

<?xml version="1.0" encoding="utf-8"?>
<svg width="120" height="120" viewBox="0 0 120 120" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
    <defs>
      <linearGradient id="Gradient1">
        <stop class="stop1" offset="0%"/>
        <stop class="stop2" offset="50%"/>
        <stop class="stop3" offset="100%"/>
      </linearGradient>
      <style type="text/css"><![CDATA[
        .stop1 { stop-color: red; }
        .stop2 { stop-color: black; stop-opacity: 0; }
        .stop3 { stop-color: blue; }
        ]]>
      </style>
      <svg id="fakeIcon1">
        <rect x="10" y="10" rx="15" ry="15" width="100" height="100" fill="url(#Gradient1)"/>  
      </svg>
      <svg id="fakeIcon2">
        <rect x="10" y="10" rx="15" ry="15" width="100" height="100" fill="url(#Gradient1)"/>  
      </svg>
    </defs>
</svg>