Oklahoma rose rock is actually not a true rock, but a concretion, a hard, rounded mass formed within sedimentary rock. These concretions are often made of chalcedony, a cryptocrystalline form of silica.

While chalcedony itself has a Mohs hardness of 6.5 to 7, the hardness of Oklahoma rose rock can vary depending on the specific composition and amount of other minerals present.

Here's a breakdown:

* Pure Chalcedony: 6.5 to 7 on the Mohs scale.

* Rose rock with significant quartz content: Can be harder, potentially approaching 7 on the Mohs scale.

* Rose rock with other minerals: The hardness can be lower than 6.5, depending on the specific minerals present.

Therefore, it's difficult to give a precise Mohs hardness for Oklahoma rose rock.

To be more specific, you would need to analyze the specific rock sample you are interested in.