Can anyone identify this stone?

[RazorMaven]

I am trying to identify this stone. Anyone out there know what it is and its rarity/value? It appears to have been used with oil and it mounted on a base that says "PATENTED APRIL 26 1870"

http://picasaweb.google.com/115156148426005505403/MysteryStone#5485746123377296514

http://picasaweb.google.com/115156148426005505403/MysteryStone#5485746132843078642

http://picasaweb.google.com/115156148426005505403/MysteryStone#5485746147453353938

http://picasaweb.google.com/115156148426005505403/MysteryStone#5485746155384781058

http://picasaweb.google.com/115156148426005505403/MysteryStone#5485746169331231426