"Sandstone" is one of nature's garbage cans: it can have anything in it, be almost any color that occurs in nature, and be any thing from just barely indurated to well indurated (indurated is geologist for "made rock-like"). There are more different kinds than you can shake a stick at, and even more geological names for them (subgrawacke, anyone?) Some sandstones, as LW states, are highly friable. Some (such as that found on the north shore of Lake Superior) have to be cut with an oxygen lance. These look good for a well indurated sandstone with a fine grain size.