The lemon juice and oil test
It is time to select your granite for your kitchen countertops. What should you look for? Two things: Absorbency and acid sensitivity. You do NOT want a stone that is too absorbent, and you do NOT want a stone that is mixed with calcite (the main component of marble and limestone).
The Lemon Juice and Oil Test will help you determine the suitability of any stone you are considering.
Collect a sample of any stone you are considering. Line them up on a table or countertop, dust them thoroughly, then spill a few drops of lemon juice and cooking oil on each one of them. If you notice that where the juice and the oil hit the stone, its surface turns dark im-mediately, eliminate them as an appropriate candidate.
If you notice that the juice and the oil take a little time to get absorbed (a half a minute or better), then you have a stone whose absorbency can be eﬀectively controlled with a good-quality impregnator.
If you finally notice that some samples will not absorb anything within, say, half an hour or so, then you may have a winner. That stone will not even need to be sealed.
Now, how to eliminate the word ‘may’ from the equation? The answer in another question: Why use lemon juice instead of, say plain water? as you’re not just look-ing to determine the absorbency of the considering, also want to determine that your samples are 100% silicate rocks to some stones—which may be traded as granite of calcite. If there’s even a little calcite in the stone, it will (citric acid) and, when you wipe your spills dry, you will notice a dull spot of the same shape of the lemon drops. In such case, once again, these stones would not be appropriate for a kitchen countertop. If instead it’s still nice and shiny under where the drops were, then you eliminated the ‘may’ factor!