Also known aschunalimequicklimeslaked lime
If at least 6 ft of soil is filled above the place where a bone lies, even a cremation ground beneath causes no trouble, provided the 16 sanskars of the land are then performed on top.
Lime (choona)
Over the spot where a bone or a cremation ground lies
It can be made on kitchen tiles, but a whitewashed surface is a must for the test. Make it in the earth (prithvi) tatva of Surya swar.
Lime is dissolved and spread over the whole land at the bottom. The complete method is taught with the 16 sanskar of land.
Removing the bone is not enough; the land needs its rites, just as a house is purified after a death. Do a vastu registry with five coconuts (four corners and the bone spot), remove the affected soil, do agni sanskar with mango wood, ghee and camphor in 16 places and float the ash in flowing water, purify with water and mantra, sprinkle gomutra and plaster with cow dung, put lime and sulphur in the pit, keep a lamp burning there for 24 hours, and mix a little mercury into the soil and the four corners. If the shilanyas had already been done, it is broken and must be redone after purification.
Their mortar was lime (chuna) made by burning limestone, which formed hydrated calcium carbonate and captured the full energy, so many such buildings still stand after thousands of years. Cement replaced it, but its life is only about 75 years and no manufacturer guarantees it beyond 100 years. Lime also absorbs negativity, which is why whole houses were once whitewashed with it.