A source of this picture states:
This image is a work of the "Minerals in Your World" project, a cooperative effort between the United States Geological Survey and the Mineral Information Institute. The images were featured in the "Minerals and Materials Photo Gallery" on the website of the U.S House Subcommittee on Energy and Natural Resources. As a work of the U.S. federal government, the image is in the public domain.
(There is a 360x320px-version also.) Iron ore is mostly found in the minerals hematite (this picture) and magnetite (also a very nice picture). This downscaled version of the original seems to have a dark blue frame, is that intentional or an artifact? I would prefer a non-framed version.