Restoring mosaics in NYC

Ms. Rosen, 43, is an art restorer who works mostly on paintings, here and in Italy, where she helped restore ceilings at the Vatican. But for the past two months, she has been caring for another kind of patient: a set of rare mosaics depicting the Stations of the Cross in the Church of St. Ignatius Loyola, on Park Avenue at 84th Street. The cleaning of the mosaics, part of a continuing refurbishment of the church, was completed last week, in time for Holy Week next month, during which the Stations are the centerpiece of the Good Friday liturgy.

Although soot and grime caused by candles, incense and radiators have all but obscured their beauty, the 14 lustrous works, which were designed and manufactured a century ago in Venice, are by any reckoning a stunning piece of art, a tour de force in thousands of colors.