The mass of the water displaced is equal to the difference between the final volume of water and the initial volume of water:
$$Mass\ of\ water\ displaced = 85\ mL - 50\ mL = 35\ mL$$
Since 1 mL of water has a mass of 1 g, the mass of the water displaced is 35 g.
Step 2: Calculate the density of the stone.
The density of the stone is equal to its mass divided by its volume:
$$Density\ of\ stone = \frac{75.0\ g}{35\ mL} = 2.14\ g/mL$$
Therefore, the density of the stone is 2.14 g/mL.
