Passing variable through Remote Function not working?

I've been trying to make a tool which allows you to mine rocks depending on the level etc. I made a remote function so the Variable of rockhit could go to the server side. I think it is not working because Mouse is something only used on the Client side, I could be wrong though.

Here is my script so far:

Client:

local Pickaxe = script.Parent
local PickaxeHitSound = script.Parent.PickaxeHit
local ToolBreakSound = script.Parent.ToolBreak
local Durability = script.Parent.Durability

local Player = game.Players.LocalPlayer
local Mouse = Player:GetMouse()
local RemoteEvent = Pickaxe:WaitForChild("RemoteEvent")

local Debounce = true
local Delay = 1

function slash()
	local anim = Instance.new("StringValue")
	anim.Name = "toolanim"
	anim.Value = "Slash"
	anim.Parent = Pickaxe
end


Pickaxe.Activated:Connect(function()
	if Debounce then
		Debounce = false
		slash()
		
		if Mouse.Target.Name == "CoalRock" then
			local rockhit = Mouse.Target.Parent
			RemoteEvent:FireServer(rockhit)
		elseif Mouse.Target.Name == "BronzeRock" then
			print("Pickaxe too low level")
		elseif Mouse.Target.Name == "GoldRock" then
			print("Pickaxe too low level")
		else
			print("Error")
		end
		
		wait(Delay)
		Debounce = true
	end
end)

Server:

local Pickaxe = script.Parent
local RemoteEvent = Pickaxe:WaitForChild("RemoteEvent")

RemoteEvent.OnServerEvent:Connect(function(rockhit)
	print(rockhit)
end)

If anybody could help me out that'd be really appreciated.