.mce-i-cjt-blocks-list-tinymce-button {
    background-image: url('../images/blocks.png') !important;
    opacity: 0.6; filter:alpha(opacity = 60%)
}
.mce-i-cjt-blocks-list-tinymce-button.cjt-loading {
    background-image: url('../../../../../../../framework/css/images/loading.gif') !important;
}
.mce-i-cjt-blocks-list-tinymce-button:hover {opacity: 1; filter:alpha(opacity = 100%)}