SOURCE

<div class="sk-fading-circle">
  <div class="sk-circle"></div>
  <div class="sk-circle sk-circle2"></div>
  <div class="sk-circle sk-circle3"></div>
  <div class="sk-circle sk-circle4"></div>
  <div class="sk-circle sk-circle5"></div>
  <div class="sk-circle sk-circle6"></div>
  <div class="sk-circle sk-circle7"></div>
  <div class="sk-circle sk-circle8"></div>
</div>

.sk-fading-circle {
  width: 48px;
  height: 48px;
  position: relative;
  background-color: rgba(0, 0, 0, 0.6);
}

.sk-fading-circle .sk-circle {
  width: 100%;
  height: 100%;
  position: absolute;
  left: 0;
  top: 0;
}

.sk-fading-circle .sk-circle:before {
  content: '';
  display: block;
  margin: 0 auto;
  width: 4px;
  height: 11px;
  border-radius: 2px;
  background-color: #ffffff;
}

.sk-fading-circle .sk-circle2 { transform: rotate(45deg);}
.sk-fading-circle .sk-circle3 { transform: rotate(90deg);}
.sk-fading-circle .sk-circle4 { transform: rotate(135deg);}
.sk-fading-circle .sk-circle5 { transform: rotate(180deg);}
.sk-fading-circle .sk-circle6 { transform: rotate(225deg);}
.sk-fading-circle .sk-circle7 { transform: rotate(270deg);}
.sk-fading-circle .sk-circle8 { transform: rotate(315deg);}

@-webkit-keyframes sk-circleFadeDelay {
  0%, 39%, 100% { opacity: 0; }
  40% { opacity: 1; }
}

@keyframes sk-circleFadeDelay {
  0%, 39%, 100% { opacity: 0; }
  40% { opacity: 1; }
}

.sk-fading-circle .sk-circle:before {
  animation: sk-circleFadeDelay 1.5s infinite ease-in-out both;
}

.sk-fading-circle .sk-circle2:before {animation-delay: -1.3s; }
.sk-fading-circle .sk-circle3:before { animation-delay: -1.1s; }
.sk-fading-circle .sk-circle4:before { animation-delay: -0.9s; }
.sk-fading-circle .sk-circle5:before { animation-delay: -0.7s; }
.sk-fading-circle .sk-circle6:before { animation-delay: -0.5s; }
.sk-fading-circle .sk-circle7:before { animation-delay: -0.3s; }
.sk-fading-circle .sk-circle8:before { animation-delay: -0.1s; }