What do you this rock weighs?

[Z-Michigan]

I would have guessed only 400-600lbs. I guess I would have been wrong. Hard to know with you saying the right side of the rock extends well beyond the photo! I have lifted rocks as big as what's visible in my FEL bucket without a problem - but I have 2100lbs lift to full height and rated 3500lbs to mid height. Now you have me wondering how heavy the big rocks on my property are - some are probably over 20 cubic feet (I didn't move them).

 

[hitekcountry]

Here is a rock (rock #1) that measures 36x30x18 which = 11.25 cft. My FEL lifted it without any problem so it has to weigh less than 1500 lb. or less than 133 lbs/ cft. The other rock (rock #2) measures 36x24x24 which works out to be 12 cft. And my FEL lifted that without any problem so again that has to be less than 1500 lbs or less that 125 lbs per cft.

So if <125 lbs/cft is a good number (looks to be the same type rock as yours) than your rock should weigh something less than 8x125 or no more than 1000 lbs

If you're saying the rock weighs around 1500 lbs and is about 8 cubic ft than the rock weighs around 187 lbs/cf, that's more than granite. --- I don't think so.

I'm going to say Wroughtn Harv is probably right.

 

[hitekcountry]

Here's a rock that I (I should say my tractor) couldn't lift, had to just push it around. I believe its granite, and I would est. it is in excess of 3000 lbs. End to end it's the same width as the FEL bucket 66".

 

[gladehound]

We have at least two distintly different types of rock here. One is heavy and one is light. The heavy kind is greyish. May be granite or something else, don't know. The light kind is brownish. The grey rocks must be ~50% more dense than the brown rocks.

Consider this.. The tractor weighs 2200 pounds without the loader. The loader adds 710 pounds right to the front axle. So there must be at least 1500 pounds on the front end. The front end felt like about 15O pounds with the rock on the back. And the rock wasn't as far from the rear axle as the front tires were. You can do the math.

My 8 cubic feet is probably conservative. It's hard to estimate the volume of an irregular shaped rock. It would be easy to over estimated the volume of a rock and thus underestimated the density.

 

[gladehound]

We have at least two distintly different types of rock here. One is heavy and one is light. The heavy kind is greyish. May be granite or something else, don't know. The light kind is brownish. The grey rocks must be ~50% more dense than the brown rocks.

Consider this.. The tractor weighs 2200 pounds without the loader. The loader adds 710 pounds right to the front axle. So there must be at least 1500 pounds on the front end. The front end felt like about 15O pounds with the rock on the back. And the rock wasn't as far from the rear axle as the front tires were. You can do the math.

My 8 cubic feet is probably conservative. It's hard to estimate the volume of an irregular shaped rock. It would be easy to over estimated the volume of a rock and thus underestimated the density.

 

[dmg]

I will Guess........and "Guess" I do............1800lbs?

 

[gladehound]

There have been a bunch of different density estimates used in this discussion so I had to go an do some research on my area. What I found is that the primary rock that forms the hills where I live is called Diabase and has a density of 2.6-3.0 g / cc. So that equates to 161 - 186 pounds per cubic feet. This is likely what the rock in the picture is.

There is a chart on the density of various rocks at this web adress:

Rock Types and Specific Gravity

Most of the rocks are between 2.3 and 3.0 g / cc. Granite is less variable than most types and is listed as 2.6-2.7 g / cc. Which is right in the middle, making me wonder why it has a reputation for being dense. But all this new information does is widen my origional estimate to 1288 - 1674 pounds. Although if it was 1288, my 3 pt should have lifted it.

 

[saltman]

I am not sure how accurate the 3pt rating or FEL ratings are I think they are conservative. I am guessing your rock is just about 1500 pounds and I think the rock in this photo is about 1800 pounds or more based on the table from the site you listed. You have my curiosity up now and I'll have to measure that rock tomorrow. One thing I do know is rock types and yours looks more like basalt than granite you can easily tell by it's hardness. Basalt is much harder. The rock in my FEL is granite like 99% of the rocks I own.. (makes me feel rich to own so many)

 

[gladehound]

I think determining between Basalt and Diabase is splitting hairs for someone like me... I don't know my rocks too well. I found the link below which indicates that these rocks are very similar

Basalt - Wikipedia, the free encyclopedia

"The term basalt is at times applied to shallow intrusive rocks with a composition typical of basalt, but rocks of this composition with a phaneritic (coarse) groundmass are generally referred to as dolerite (also called diabase) or gabbro"

Looking at pictures, my rock looks more like basalt than what they describe as diabase, which sounds like it is a variation of basalt. But I couldn't find a picture of diabase. I only found that the hills in my area are supposed to be made of diabase.

If that loader you have is similar to the 430 my cousin had on his 4300, even though it was only rated to 1300 pounds at full hieght, you could lift a 2500 pound pallet with forks a foot or two to move it around.

 

[SPYDERLK]

Here's a rock that I (I should say my tractor) couldn't lift, had to just push it around. I believe its granite, and I would est. it is in excess of 3000 lbs. End to end it's the same width as the FEL bucket 66".

Makes you wish for independent front brakes when the back end gets light!
larry