How can I mask white spots in pink marble?

["George Graham" <georgergraham@zzzzzzzzzzz>]

Michiel,
seems to me that either frosting and texturing the surface to hide the spots
(which reduces the beauty of the stone), or drill out the spots and fill
with a stone and epoxy mix.
There are some tricks to filling and patching.
Use a drill to remove the offending spot. Go in at least 3\8", (1 or 2 cm),
so you have straight sides on the hole so the glue has something to lock on
to.
Break out sections of the top edge of the drill hole so as to destroy the
circle outline of the drill hole.
Brake up pieces of the marble to create a mix of particles of different
sizes that simulates the granular look of the stone. If the mixture is too
uniform in size , it will stand out as a patch.
Use a UV resistant epoxy, that is clear. Epoxy and polyester resin glue
products are improving so fast that you will have to do some research for
what is best for you. Maybe someone else on the list can recommend a current
glue that does not yellow with age and UV exposure. I've seen that the epoxy
I've used on outdoor projects  does yellow and darken with age, despite the
manufactures claims. It just takes longer to happen. Try to keep the
repaired side out of direct sunlight.
Make sure the chips of stone are on top of the filled hole , and over fill
the hole so when the patch sets up , it will not shrink below the surface.
After you have sanded away the excess, you may have to go back and fill air
bubble holes and other gaps.
Beware of sanding into the surface of the existing stone at individual
repairs. You will create a depression that will really stand out on a flat
surface. If possible , sand and refinish the whole side so you have a
uniform finish.
I almost forgot, wet the sides of the hole with glue before pack in the
patch.
Good luck,
George Graham
http://www.grahamsculpturestudio.com