Webkit Font Displays in Chrome but not in Desktop or Mobile Safari. Have Confirmed Embed Code.

I'm trying to use the font Chantal on a few pages on a website I manage and it is configured as per the Web Project CSS instructions, but it is not displaying the font in either the desktop or mobile Safari browser. I've tried modifying the font-family syntax in Safari's Web Inspector, but I'm not having any success. Can anyone help me more?

The CSS I have is as follows:

font-family: chantal, sans-serif;
font-weight: 300;
font-style: italic;