I found a pink slab of stone with a nice dip in the middle and thought of using it as a mortar for grinding spices.

Are there any stones whose makeup could potentially leach toxins?

  • 2
    There are stones that contain toxic minerals (like arsenic, mercury, lead, etc) so I would confidently identify the stones you're using. Mar 31, 2016 at 18:06
  • It looks like pink granite. I will get a pic but I am new here and don't really know how to do it.
    – SwampWitch
    Mar 31, 2016 at 20:00
  • Thanks...everyone; I'll try harder to find out the type I think I have so you can delete this and I will have a better formulated question...or have answered it ...
    – SwampWitch
    Mar 31, 2016 at 23:34

1 Answer 1


Granite, marble and jade are all common stones used for mortar/pestle combinations. There are probably many other stones that are safe, but you want to avoid the following:

  • anything that is porous such as sandstone or dolomite
  • anything that will break apart easily, mainly sedimentary stone
  • anything that might expose you to metal toxicity such lead or cadmium
  • anything with organic matter attached
  • anything that reacts chemically to whatever it is you're grinding
  • Where safety is concerned, why avoid porous stones such as sandstone? I would have thought "because they may wear off into your food," but "break apart easily" is your next point.
    – Loduwijk
    Jun 25, 2018 at 19:37
  • Porous stone allows food particles to accumulate at the subsurface level, leading to bacteria growth, while nonporous stone limits accumulation to the surface area which can be easily cleaned. You could mitigate accumulation through the regular treatment of the stone (e.g. with food grade wax) but you'd likely lose some of the grinding benefits and given the nature of grinding you might have to treat it frequently.
    – furtive
    Jun 27, 2018 at 14:59

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