The Village of Chalk

By Gino Melchiorre

Caption: Lalli-Persiani Palace-Building[1]    

A museum for chalk but also an entire village inside a museum: this is an old idea that has re-emerged recently (1996) to safeguard what is left of the most typical work traditions of Gessopalena[2], extraction and working of the chalk rock. The original nucleus of the village lies on a mass of this chalk rock. In the past few months, following excavation work, various buildings of the Old Village have been recovered. After the war, following the frightful collapse of the eastern wall of rock that lies above the old quarry, the "Pretalucente[3]" (Shining Stone[4]) was irredeemably disfigured.

Although various premises belonging to the Town Hall are available to exhibit craft and agricultural tools and equipment, old photos and other things that visually represent the history of chalk workers, none of them has the typical characteristic structure of a "living" museum, rather than a "dead" one; not even some of the recently restructured buildings in the Old Village.

There is, however, a private building which has all the characteristics needed for a live museum, as old as the Old Village itself, of which today it represents the most interesting part, even if it is little known. This is the huge cellar of the Persiani Palace, whose owner, Aureliano Lalli Persiani, has said it is available for the Town Hall to make use of, provided they equip it as a museum. The manner and timing of its use are yet to be decided and verified. This is an opportunity that the Town Hall and the cultural associations of Gessopalena, as well as the citizens interested in the history and guardianship of their wild native village, cannot afford the luxury of allowing to pass them by. This opportunity will not arise again, and, with the demographic crisis that is taking place in our villages, (if we do not grasp it) this last possibility of fixing with dignity a part of our historic past and leaving it to the few descendants who will follow on, will disappear.

The cellars of the Persiani Palace, which figure as the only almost intact bastion placed at the entrance of the Old Village, were dug out of the chalk. Until the 1940’s and 1950’s they were the site of an olive-press, a stable – which later became a garage – and a normal warehouse for food products. Visiting the cellars one has the impression of entering and exiting a series of Chinese boxes, with steps, windows and French doors inserted and carved into the rock, like in olden times. It is a fascinating experience, but unfortunately it has been put in danger by recent repaving, undertaken by the Town Hall, of the overhanging little road, Via Castello, at the entrance to the village. This gives rise to continuous flooding of the Persiani cellars due to infiltration by rain water which drips off the chalk walls, endangering them in the long run, and also the structure of the Palace. The foundations of this building rest on the underlying rock walls. Another problem is that the restructuring and support works carried out by the owner himself in the last few years, now risk being irredeemably worn out.

Aureliano Lalli Persiani did not put up controversial posters, nor did he write to the newspapers, or use any other gaudy methods. He simply let the problem be known, which arose a year ago when a local firm repaved about 20 metres of Via Castello.

Renewing the water resistance (impermeability) of the little road would not be excessively costly, rather there would be a gain for the entire "chalk community" of Gessopalena, for they would then have full use and enjoyment of the cellars of Gessopalena’s oldest Palace (which in its present form dates back to the 17th Century). Its owners, the Persianis, have been protagonists in the history of the province of Chieti for several hundred years, but even this is something the "chalk" villagers of Gessopalena are ignoring.

Translator's notes:

[1] The Italian word "Palazzo" means both "Palace" and "Building". It is difficult in this case to know which of the two words it would be better to use, either could be appropriate, hence I have used both!

[2] Gessopalena - This small mountain village in Abruzzo takes its name from the chalk quarries of the area, and has a wealth of medieval monuments. It lies to the right of the Aventine Valley. Gessopalena dominates the surrounding countryside, including the "La Morgia" rock formation see:-

Historically this domination was useful in its defence, and also the village could protect the way to the rich pastures of the Majella when necessary. Gessopalena was inhabited in prehistoric and Roman times; its written history dates from the 12th Century AD.

In the early Middle Ages Gessopalena consisted of a group of houses clinging to a big rock called "Pietra Lucente" (Shining Stone) on top of which was an ancient castle. At that time Gessopalena was the main commercial centre in the Aventine valley. Later on the population moved downwards along the ancient "Via Peligna" to the site where the modern town is today.

[3] "Pretalucente" (dialect) = "Pietra Lucente" or Shining Stone – an old name given to the rock on which the ancient village of Gessopalena was built.

[4] Shining Stone – The rock underneath Gessopalena is Gypsum (Hydrated Calcium Sulphate) used to make plaster of Paris, blackboard chalk, wall board, some cements, paint filler, ornamental stone, fertiliser etc. Since the mountainside on which the ancient village lay was a huge mass of gypsum, due to its particular crystalline structure, from some angles it can take on a certain shine and depending on how the rays of the sun would strike it, at certain times of day it would become especially brilliant and shining.

Gypsum is one of the more common minerals in sedimentary environments. The largest deposits known occur in strata from the Permian age. It is a major rock forming mineral that produces massive beds, usually from precipitation out of highly saline waters. Since it forms easily from saline water, gypsum can have many inclusions of other minerals and even trapped bubbles of air and water.

Gypsum has several variety names that are widely used in the mineral trade:-

  • Selenite is the colourless and transparent variety that shows a pearl like lustre and has been described as having a moon like glow. The word selenite comes from the Greek for Moon and means moon rock.
  • Satin Spar is another variety; it has a compact fibrous aggregate. This variety has a very satin-like look that gives a play of light up and down the fibrous crystals.
  • Alabaster is a fine grained massive material and is an ornamental stone that has been used in fine carvings for centuries, even eons.
  • Desert Rose - Rosette shaped Gypsum with brown sand inclusions.
  • Gypsum Rock - Rock composed mostly of the mineral Gypsum, but also contain impurities such as Calcite, Anhydrite, Rock Salt, Dolomite, Limonite, and clay.

Gypsum is one of the most widely used minerals in the world and it literally surrounds us every day.  Most gypsum in the United States is used to make wallboard for homes, offices, and commercial buildings; a typical new American home contains more than 7 metric tons of gypsum alone.  Moreover, gypsum is used worldwide in concrete for highways, bridges, buildings, and many other structures that are part of our everyday life.  Gypsum also is used extensively as a soil conditioner on large tracts of land in suburban areas, as well as in agricultural regions.

Industrial uses:-

  • Blackboard chalk
  • Sheetrock or wallboard, a construction material
  • Plaster. a construction material.
  • Dental moulds
  • Surgical casts
  • Paint filler
  • Toothpaste
  • Gesso
  • Casting metals
  • Solidifying earth (cast earth construction)
Name Origin: Gypsum from the Greek, gyps meaning "burned" mineral.

Selenite from the Greek in allusion to its pearly lustre (moon light) on cleavage fragments.

The word gypsum is derived from the Greek meaning 'to cook', in reference to the burnt or calcined mineral. Because the gypsum from the quarries of the Montmartre district of Paris has long furnished burnt gypsum used for various purposes this material has been called plaster-of-Paris.

In a small number of Gypsum specimens, water gets trapped inside a crystal in a hollow channel while the crystal forms. When such a crystal is rotated, a water "bubble" moves around inside it toward the lowest point in the channel. Such specimens are considered a mineralogical oddity, and are very much sought after by collectors.

Gypsum is an industrially important mineral. It is the primary ingredient of plaster-of-Paris (finely ground Gypsum) and is also used in the production of cement. It is also the main component of sheet-rock. It is used as a flux for creating earthenware, and can be used as a fertilizer. The variety Alabaster is carved for ornamental use, such as artistic sculptures and pottery. It is porous and is therefore easily dyed. The fibrous Satin Spar variety is sometimes cut into cabochons for collectors because of its strong cat's eye effect.
Fine Gypsum specimens are very popular among mineral collectors, especially the varieties Selenite and Desert Rose.


1. 2. 3. 4. 5. 6. 7.

1. Silent crystal
2. Brown crystal cluster
3. Gypsum "Desert Rose"
4. Group of fragile acicular crystals
5. Platy rosette crystals
6. Long, slender, bent crystal
7. Satin Spar

Heating gypsum above approximately 150°C (302°F) partially dehydrates the mineral, by driving off exactly 75% of the water contained in its chemical structure.

The dehydration (specifically known as calcination) begins at approximately 80°C (176°F) and the heat energy delivered to the gypsum at this time (the heat of hydration) goes into driving off water (turning it into water vapor), not into increasing the temperature of the mineral. As water is lost, the temperature of the gypsum slowly increases until all the water has been removed, then begins rising normally at a quicker rate. The ability of hydrated gypsum to remain at relatively low temperatures, even if a flame is applied directly to it for a short period of time, is exploited by drywall to confer fire resistance to the wooden frames of houses and other buildings. Even if a fire is impinging directly on a sheet of drywall, the wood frame behind it will remain at a relatively low temperature, preventing the destruction of the wood and the collapse of the structure, (until eventually too much water has been lost from the gypsum, when the wood will heat up and then burn).

The partially dehydrated mineral is called calcium sulphate hemihydrate or calcined gypsum (though more commonly known as plaster of Paris). Calcined gypsum has an unusual property: when mixed with water at normal (ambient) temperatures, it recombines with the water that was driven off during calcination, and then sets to form a strong gypsum crystal lattice; this property is made use of in forming plaster casts to set broken bones.

Most minerals, when rehydrated, simply form liquid or semi-liquid pastes, or remain powdery. Gypsum, on the other hand, forms a strong crystal structure immediately upon receiving the water, and this phenomenon is responsible for gypsum's ease of being cast into sheets (for drywall), sticks (for blackboard chalk), molds (to set broken bones, or create molds for metal casting), and other forms. Small amounts of calcined gypsum are added to earth to create strong structures directly from cast earth, an alternative to adobe (which loses its strength when wet).


Bladed rosettes of gypsum.
Scale: Specimen size 6 cm.
© Dave Barthelmy


Pencil-sized acicular crystals of gypsum.
Location: Naica, Chihuahua, S.A., Mexico.

Scale: Specimen size 5 cm.
© Dave Barthelmy

Gypsum rocks are sedimentary rocks made up of sulphate mineral and formed as the result of evaporating sea water in massive prehistoric basins. It is very soft and is used to make Plaster of Paris, casts, moulds, and wallboards.

© Amici di Torricella

Translation courtesy of Dr. Marion Apley Porreca

  <=Back to Index