Roberto Velázquez Cabrera

January 10, 2001

Figure 1. Black stone aerophone

The objective of this short paper is to update a previous study [1], of march 2000, providing additional information and comments on the black stone aerophone (Figure 1). Strictly, it is very difficult to prove the ancient use of these black stone. However, after reading the biography [2] of the collector Francisco Beverido Pereau and books related with his work and the olmec culture and some searching in Internet, I lucubrated [3] on the possible origin, material and use of the analyzed stone, considering the following bases:

  • It could have been made in the olmec culture from the Gulf of Mexico coast, maybe in San Lorenzo Tenochtitlán. Some of Beverido´s works and discoveries were made on this archaeological site, including his thesis [4], and this site is well known as one of the best ancient lapidary centers.
  • Its possible origin is the preclasic, nearly 3,000 years ago, when it is suppose that the olmec and Mexican (and American) civilizations were born.
  • The stone seems [5] ilminite (FeTiO3), a natural ore for titanium. Ilmenite [6] is hard (nearly 6 in Mohs scale). It is metallic mate black. Density 4.7 (g/cm3). Its fusion point is 500 C. It can be diluted with sulfuric acid. It is very difficult to make without mechanical tools and hard abrasives (=> 9, as silicon carbide and diamond). I know this is difficult because I practiced the lapidary art on hard stones [7].
  • The little stone may be an aerophone (whistle). I found It can generate loud sound with an compressed airflow. This is the main characteristic of an aerophone. There is evidence that similar ancient whistles have been used in Mexico and in other zones in several materials [8 and 9]. Soft stone in France, ivory in Greenland, ceramic in South America and metal in Turkey.
  • The whistle may belong to an extraordinary Mexican family of aerophones that can generate colored noise of secret use. The stone has a similar structure and generated noise. The sound was analyzed with digital spectrograms. It has complex non periodic frequency components. The generated sound is very similar to those obtained from replicas of this noisy family of Mexican aerophones. It has 3 conical holes with its centers located in the same plane. This structure is a necessary condition for the good operation of this very special sounding mechanism.

Recently, I got a very interesting paper [10] from Ann Cyphers and Anna di Castro on "Los artefactos multiperforados de ilmenita en San Lorenzo" (Ilminite multi-drilled artifacts in San Lorenzo). Their information supports my previous expectations on the culture and zone origin, date and material, because they are the same.

Ann and Anna comment the following extraordinary discoveries (in quantity an localization) of very similar (in structure) ilminite artifacts:

  • 6 complete stones and one broken were found in the north of Monument 17, a colossal head located at the east of the central-south of San Lorenzo Peninsula [11].
  • 10,000 almost all complete stones were found in the hinterland of San Lorenzo, nearly 4 km to the south of the regional center, in the secondary site of Loma Zapote, at one side of the sedimentary river, possibly from the inferior preclassic.
  • Nearly 150,000 or more than 4.5 ton of artifacts were found in the site "A4 Ilmenitas", in three concentrations. The previous sites are olmec zones.
  • 2,000 black stones without holes (including 24 broken stones with holes and one complete with three holes) were found in Plumajillo, Chiapas [12].

They comment on previous papers and studies and they provide relevant opinions. The stones could be used by selected groups from the elite using a specializes technology. The row material could be transported from other zones, like Chiapas. They mention several interesting possible ancient uses of ilminites including the following: beds and pendants for personal adornment, drill to make fire, weights for fishing nets or for átlatl and hammer. And they provide their own theory: to sustain the stick of a drill with bow.

The previous uses were possible, but to do these utility functions only one hole is required and their special 3-holes structure and alignment is nor necessary. I used a stone with some similar physical characteristics (hardness 5 - 5.5): obsidian (iztete), to test the hypothesis that if it can sustain a drilling wood stick.

  • The stone must be in a size adequate to be sustained by the hand (5 x 5 x 1 cm). The actual ilmenita size (3 x 2 x 1.5 cm) is not adequate for this purpose.
  • In less than an hour of operation (using an electrical drill), the friction between obsidian and wood smoothed and polished the internal stone resonator surface. As the internal ilmenite resnator surface is not polished, it was not used in that way.

I made a copy of the whistle with obsidian to test the required time to make the three holes. I spent almost 8 hours in this process using an electric drill, an iron stick as cutter, silicon carbide as abrasive, a reservoir for the water used as cooler and a press to fix the stone and to align the holes. That means that the required time to make the holes manually may be weeks or months, depending of the selected tools and abrasives.


  1. The most relevant work to be done is to test if the ilmenites from San Lorenzo have sonic properties. I think it is likely for many stones, because it seems they are very similar in structure.
  2. The discovery of massive quantities of similar artifacts gives more importance to the studies on their properties and possible uses of aerophones. If it is possible to test a sample of aerophones, and to record their sounds, it is possible to use other signal analysis techniques like sound characterization.
  3. It is recommendable to test all the available microanalysis (micro wear?) techniques to see if it is possible to find recognizable small amount of material, mechanical traces or signs related with the ancient use of ilmenites or their construction technology [13].
  4. The next question is about the use of their colored noise. There is relevant evidence that ancient whistle could be used for magic or therapeutic uses, if they are played in groups [14]. To prove this use for the ilmenite case is a matter of future advanced research.

There are several interesting relations or coincidences? (see Figure 2): Near San Lorenzo, in Soteapan was found other extraordinary aerophone that produces colored noise and it has three resonating chambers called "Gamitadera", analyzed in a previous paper [15] and; In that Zone, in Catemaco there are healers using ancient techniques.

Figure 2. Map with the South of Veracruz State, and San Lorenzo, Soteapan and Catemaco.


  1. Velázquez-Cabrera, Roberto, "Black stone aerophone". The Spanish version of this paper was presented in the Computing International Conference CIC-2000, held in the National Politecnic Institute, Mexico City, on the 16h of November, 2000. (http://www.geocities.com/rvelaz.geo/bstone/bstone.html).
  2. Biografía de Francisco Beverido Pereau (Actualidades Arqueológicas) http://swadesh.unam.mx/ActualidadesWWW/10/texto/franciscobeverido.html.
  3. Invitation to the conference "Aerófono de piedra negra" of Roberto Velázquez Cabrera. (http://www.geocities.com/rvelaz.geo/tesis/invitacion.html). The invitation and my lucubration was posted in MIMForum (Musical Instruments Makers Forum) (http://www.mimf.com).
  4. Beverido Pereau, Francisco, "San Lorenzo Tenochtilán y la civilización olmeca", MSc thesis, Universidad de Veracruz, Jalapa, 1970.
  5. Kurin, M. And Egorov N., Field Manual of Minerals, MIR Publishers, Moscow, 1976. With the tables of this extraordinary Manual and the physical properties of the stone (lustre, color, hardness, type of aggregation and density) the ilemnite identification was almost direct.
  6. Sinkankas, John, Gem Cutting. A Lapidary´s Manual, Second Ed. Van Nostrand Reinolds, 1962, ISBN 0-442-27623-0. This is my "Bible" for lapidary work.
  7. Ilmenita. (http://www.uned.es/cristamine/fichas/ilmenita/ilmenita.html). It provides the properties of ilmenita.
  8. Armengaud, Cristine, "Musique Vertes", 3. Ed. Cristine Bonneton Editeur, 1984. ISBN 2-862353-044-1. This reference was provided by Uli Wahl. He is an expert and has a site on Kite (Aeolian) Musical Instruments. (http://members.aol.com/woinem1/index/litratur.htm)
  9. Velázquez-Cabrera, Roberto. "My First Whistle". November 2000. (http://www.geocities.com/rvelaz.geo/corcho/cup.html). A study of a whistle of this mexican noisy family of aerophones made with a metal cup of beer and used more than 50 years ago.
  10. Cyphers, Ann and di Castro, Ann "Los artefactos multiperforados de ilmenita en San Lorenzo", Arqueología, Revista de la Coordinación Nacional de Arqueología del INAH/Segunda época, 16, Julio-diciembre 1996. A copy of the paper and some comments were provided by archaeologists Norberto González and Hernando Gómez from INAH.
  11. Coe, Michael D. and Richard A. Diehl, "In the Land of the Olmec", Austin, University Press, 1980.
  12. Agrinier, Pierre, "Mirador-Plumajillo, Chiapas, y sus relaciones con cuatro sitios del horizonte olmeca en Veracruz, Chiapas y la costa de Guatemala", Arqueología No. 2, 1989.
  13. Ancient Musical Instruments Surfaces Project. McDonald Institute for Archaeological Research, University of Cambridge. http://www-mcdonald.arch.cam.ac.uk/Annrep/1998-9/postex.htm. Dr Graeme Lawson explored tuning- and performance-related aspects of bone pipes ranging in date from as late as the eighteenth century to as far back as 36,000 years ago, but it seems these projects did not include stone aerophones.
  14. Garret, Steven and Stat K. Daniel "Peruvian Whistling Bottles", JASA, Vol. 62, No. 2, August, 1977. (http://www.statnekov.com/). It is the only paper on the field of ancient aerophones published in this journal and I could not find other formal paper of this kind in any part of the world.
  15. Velázquez-Cabrera, Roberto. "Análisis Virtual de la Gamitadera", 1999. Study with replicas of an extraordinary aerophone with tree resonating chambers, from the Olmec culture of Gulf Zone. Available in Internet location: http://www.geocities.com/rvelaz.geo/tesis/gamito.doc/