These miniature nativities generally range from 1.5 to 4 inches high. They appear in many forms, such as caves, eggs, pots, and even traditional Peruvian chullo hats. The tiny inhabitants are carved by hand and and then placed inside.

Piedra de Huamanga, or Huamanga stone, is found only in the Ayacucho region of Peru. There seems to be some disagreement as to what type of rock Huamanga really is. Some sources claim it is alabastrite, a form of gypsum, while others say it is calcite. Both alabastrite and calcite are sedimentary rock, and they are very similar in appearance. Both are also white, but can be found in shades of grey, brown, pink, or other colors due to impurities. The best way to distinguish them seems to be an acid test. Calcite will bubble when acid is applied, while gypsum will not.