You want an entity known as a cross mark:
http://www.fileformat.info/info/unicode/char/274c/index.htm
The code for it is ❌ and it displays like ❌
If you want a perfectly centered cross mark, like this:
try the following CSS:
div {
height: 100px;
width: 100px;
background-color: #FA6900;
border-radius: 5px;
position: relative;
}
div:after {
position: absolute;
top: 0;
bottom: 0;
left: 0;
right: 0;
content: "\274c"; /* use the hex value here... */
font-size: 50px;
color: #FFF;
line-height: 100px;
text-align: center;
}
Cross-Browser Issue
The cross-mark entity does not display with Safari or Chrome. However, the same entity displays well in Firefox, IE and Opera.
It is safe to use the smaller but similarly shaped multiplication sign entity, × which displays as ×.