Physically, yes if you crush a stone it physically will change.
Energetic wise? Perhaps not.
Though I do not know for certain how a stone will feel for me after I have crushed it, as I've never tried.
You will not know if it feels right for you Until like Lynn said after you've asked permission, or ask it if it wants to be crushed, or stay as is.
I have been lately wanting to polish rocks. However recently have found a piece of raw Unakite. Personally I very much love raw specimens of stone. I tend to notice I feel the energy of a stone better when it is in raw natural form as opposed to a polished piece.
There are some many things you could do with a crushed stone as Lynn suggested. Carrying it on a necklace made from a small vial, or small jar.
I assume you have your own reason for crushing it?
I would do as Lynn suggested and ask permissions, as well as asking specifically perhaps if it wants to be crushed.
I have gotten into the habit of asking the stones I buy/find how they'd like to be used, or if they would like to be polished, modified in any way.
I currently do not have a rock polisher, and end up with keeping the stones in rough form.
This may change if I get a polisher. I still do like to spend time with the stone and feel out the energy when I can.
These things sometimes can be tough decisions to make. There is a beach stone I found I loved alone as a piece raw, and I recently attached it with glue to my talking stick.
I actually do regret doing this.
Energetically I personally do find stones to change. I do not feel the energy itself remains stagnant, but change does not automatically mean a negative.
There perhaps are some out there who can feel strong energy from polished stones. I notice with myself I am just learning to experiment with feeling energy of stones, and I have particulars I like as I feel more energy from certain physical attributes from the stones. Examples being like I said I feel strong energy from rough specimens of stones, and if polished I feel a lot more energy from naturally polished stones- beach stones polished by ocean water, river stones polished by river water.
I feel more energy if a stone is polished by water than if I bought polished stones that were hand polished- by rock polisher etc- online.
Good luck to you Gracey. I hope you find your answer.
Always trust your intuition.
Blessings.