I have found Indian arrow heads made from jasper, that look similar to the rock in your picture.
http://www.all-that-gifts.com/se/jasper.html
http://images.google.com/images?hl=en&q=jasper%20gemstone&revid=102872970&resnum=0&um=1&ie=UTF-8&source=og&sa=N&tab=wi
http://images.google.com/images?um=1&hl=en&tbs=isch%3A1&sa=1&q=jasper+stone&btnG=Search&aq=f&aqi=g2g-m2&aql=&oq=&gs_rfai=&start=0
http://www.gemselect.com/gem-info/gem-hardness-info.php
http://www.gemselect.com/gem-info/jasper/jasper-info.php
http://www.rocksforkids.com/RFK/identification.html
http://en.wikipedia.org/wiki/Jasper
Notice Moh’s test, and specific
gravity, this may get you started.