The answer depends on the density of the rock. A cubic foot of pumice, for example, can have a mass of around 15.6 pounds whereas minerals rich in metals such as iridium will have mass exceeding 1200 pounds.
Naturally the weight of stone/rock varies according to the type of rock. But, on average, one cubic foot of rock weighs in the neighborhood of 200 pounds.
That would depend on what it is you are weighing.
Mass is: M=V x d.
To calculate the mass you need to know the density of this rock.
1 stone weight about 14 pounds
a cubic foot of water
The weight of a cubic foot of rock will depend on the specific gravity and proportion of the minerals that compose the rock.
1 cubic yard of rock = 27 cubic feet of rock. 27 cubic feet of rock @ 6" (1/2 of foot) = 27/(1/2) = 54 sf
Limestone is a type of rock, so its weight can vary from almost nothing (a small pebble) to a million or more pounds. There is not a specific size limestone, so there is no answer for this question, other than it is a type of sediment that turned into rock.
The rock, marble, is 2.56 times as heavy as water. One cubic foot of solid marble weighs 160 pounds.
Basalt (solid)--188 pounds per cubic foot.
about 2500 pounds.
The weight of a cubic foot of rock will depend on the specific gravity and proportion of the minerals that compose the rock.
Natural rock for landscaping weighs between 1.4 and 1.7 tons
Granite weighs approximately 165 pounds per cubic foot. Sandstone weighs approximately 155 pounds per cubic foot. Factors that affect this weight include the size of the rocks and the type of rock.
1 cubic yard of rock = 27 cubic feet of rock. 27 cubic feet of rock @ 6" (1/2 of foot) = 27/(1/2) = 54 sf
If you are going to buy river stone/pebles/rock from supplier they use the "formula" Cubic Yards x 1.25 = Weight in tons. They then sell it by the ton. (say $300 per ton) But this is an approximation. If it is one very big river rock it would be a good approximation, but even then it would depend upon the density of the rock eg granite would require a bigger constant (the 1.25) than a Sandstone boulder.
For the calculus you need the density of this rock: M = V x d.
(3 x 2 x depth of the hole in feet) cubic feet
the density of most rock is between 2.2 and 3.8 so multiply the volume of your "big rock" in liters or cubic decimeters by a number between 2.2 and 3.8 to get the answer in kilograms.
100 cubic feet for every foot of depth.
1 cubic yard = 27 cubic feet so 100.00 per cubic yard equates to 100/27 = 3.7 per cubic foot. 3.00 per 5 cubic ft equates to 0.6 per cubic foot - which is definitely less than 3.7 per cubic ft.
Volume = (1,200 square feet) x (1/3 foot) = 400 cubic feet = 14.81 cubic yards