Fear Not, dear reader, all is not lost - its time for The Makeup Saviour!! In these times of shrinking pay checks and rising costs we all try to make our products last til they really are finished!!
To repair this kind of damage, you will need......
99% alcohol
Paper Towels
Q-tips
access to direct sunlight or a radiator
Lay out a paper towel - this could get a little messy!! Carefully open the container - you want to save as much of the crumbled product as possible - scoop all the pieces back into the pan, now carefully drown with as much 99% alcohol as you can get in there - snip the cotton bud off one end of the Q-tip and use it as your mixer, - your result should be a paste - as lump free as possible (especially if it is a shimmer product).
Now take another paper towel and fold until you have a small pad - maybe 5 or 6 times, press this pad onto the pan hence soaking up as much of the 99% alcohol as possible, reshape so all the product is back in its container (there could be some oozing :)) and dry in the sun or on top of a medium heat radiator.
For a shimmer product I re-brake and repeat the above steps 2-3 times just to make sure its mixed correctly, for matte powders - definitely twice - be careful not to over-dry on the radiator or it could possibly crack again - but really - Who cares - you now know how to fix it :)
This technique works with all PRESSED POWDERED shadows, blushes and pressed face powders - I have done it on Mac Studio Fix too and it works well - though it has a tendency to re-brake a lot after - regardless its a better option than throwing it out and buying a new one before time - just keep it still and in one place after you fix it - and try not to break the new one!!