Is it possible to draw a partial circle outline in CSS (open ring shape)?

Question

I\'m interested in creating a loading spinner entirely in CSS but in order to do so I would need to be able to draw a open ring shape like this:

The ring wo

Answer 1

for the pseudo version, you can also use linear-gradient (shade can be decreased or increased) and background-clip,

where it is avalaible, mix-blend-mode can make it translucide,

currentcolor and animation can also be used to animate color :

.loader {
  font-size: 1.5em;
  color: gray;
  position: relative;
  padding: 3px;
  /* make a square */
  height: 100px;
  width: 100px;
  /* center content*/
  display: flex;
  align-items: center;
  justify-content: center;
  animation: coloranim infinite 5s;
}

.circle {
  border-radius: 100%;
  overflow: hidden;
}

.loader:after {
  border-radius: inherit;
  color: inherit;
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 3px;
  background: linear-gradient(white, white), linear-gradient(0deg, transparent 40%, currentcolor 60%), linear-gradient(50deg, transparent 50%, currentcolor 52%);
  background-clip: content-box, border-box, border-box;
  z-index: -1;
  mix-blend-mode: multiply;/* if avalaible, else bg remains white */
}

.spin:after {
  animation: spin 2s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes coloranim {
  20% {
    color: tomato;
  }
  40% {
    color: purple;
  }
  60% {
    color: turquoise;
  }
  80% {
    color: green;
  }
}


/* demo purpose, use your own style wherever your loader is needed */

html {
  height: 100%;
  display: flex;
  background: url(http://lorempixel.com/800/800/food/3);
  background-size: cover;
  box-shadow: inset 0 0 0 2000px rgba(255, 255, 255, 0.3)
}

body {
  margin: auto;
}

 loading... 

http://codepen.io/gc-nomade/pen/YNbmGE