Hi Pabs
Can you post a photo of the damage?
It's not uncommon for the White Carrara to "stun" with an impact such as your stone experienced. That being the case, hiding your blemish is a little more difficult. A typical repair will only yield filling a shiny blemish.
More than likely, you'll need a little colorant(s) added to the repair, as well deciding if it is best to disguise the repair by blending it to the color of a vein vs. trying to get a matching color of the field of the stone (the white part).