locating the standard Image files

-- url of the page with the problem -- : mywebsite.com/mypage
-- HikaShop version -- : 2.2.1
-- Joomla version -- : 2.5.14
-- PHP version -- : 5.3.3
-- Browser(s) name and version -- : XXXXX x.x.x
-- Error-message(debug-mod must be tuned on) -- : Error_message

Hi Just wondering where I can locate the folder that has the standard images for "orders, card, account" etc. I can find the shortened URL in the CSS file but I dont find them in the Joomla media file manager.
The example I have used is the icon for customer account below.

icon-48-user {background-image:url(../images/icons/icon-48-user.png);}

Thanks