I use 'holy dirt' in my art.
I mix it with gesso and modeling paste. I have some from El Santuario Chimayo as well as from the original graves of the Trappist Martyrs of Atlas. I have not used the martyr's sand for a long time now - but the Chimayo holy dirt I use in my retablo art.
Read more about the holy dirt here. It is known as the Lourdes of the United States - a place of miracles. If they put sand in your holy water fonts this Lent, offer it up, recalling Chimayo. Christ said even the stones will cry out (Luke 19:40) - sand and dirt is comprised of micro sized stones. I hope they don't do that any longer - sand in the fonts - holy water is very important. That said, nothing can separate us from Christ, and he can work miracles even through dirt ... dust to dust, ashes to ashes ... God formed man from the dust of the ground, don't forget.
Everything is a grace.
Chimayo is so poor, so simple and noncommercial - it would be a good pilgrimage for the Year of Mercy.