Z. L. Tsintsov, Central Laboratory of Mineralogy and Crystallography, Bulgarian Academy of Sciences, Sofia, Bulgaria
Address: Dr. Z. L. TSINTSOV, Central Laboratory of Mineralogy and Crystallography, Bulgarian Academy of Sciences,
bl. 107 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria, E-mail: ztsintsov@ mail.bg; email@example.com
UNIQUE FINDS OF GOLDEN ARTEFACTS IN ALLUVIAL PLACERS IN BULGARIA
(Published in: Tsintsov, Z. L. 2000. Unique finds of golden articles in alluvial placers in Bulgaria. - Japanese Magazine of
Mineralogical and Petrological Sciences, 29, 2; 52-58 (in Japanese with English abstract and Supplemental remarks to
Prof. Tadato Mizota).
Abstract: Unique finds from placer deposits in the western Bulgaria are shown to discuss the interrelation among types of
articles, the gold manufacturing, the placer deposits as the source of gold and the archeological significance of the
discovery. The articles found in this area are characterized by both the gold and the precisely fine crafrs. Most of them are
identified archaeologically with those at the same age of the Chalcolithic Necropolis near Varna in the eastern Bulgaria,
where the metallic articles including copper and gold products were found in 1972 and have been considered to be of the
oldest metal culture (before 4000 BC) in the world. The finding in the western Bulgaria are also valuable in following two
facts that the sites of manufacturing gold articles were specified to be very near to the gold-placer deposits and that the
articles are comparable in various natures with those of the Varna Necropolis.
Key words: Placer deposit, Golden article, Archeology, Metal culture, Bulgaria, Varna, Chalcolithic necropolis, Sperrylite
Discovering metals is a crucial moment in the development of human society. People are interested in them since remote
past as they are part of the natural resources. Their assimilation lasted a long period of time and their qualities were used in
different ways according to the needs. This is why it is not acceptable to point out “discovering” of metals and their initial
use (Pernicka, 1994). It is not clear when and where gold was used for the first time but it influenced significantly on human
history. The history of gold becomes the history of civilization!
Several major gold-mining provinces were known in Ancient Europe as one of them was situated on the territory of Balkan
peninsula (Marfunin, 1987). Gold recovered from deposits in that region during the various periods of human history
amounts to about 1020 metric tons (Marfunin, 1987). The lands of Bulgaria, being a part of this region, always provoked
the great interest of specialists in geology, mining, archaeology and metallurgy to placer gold deposits most of which were
developed in the past on a large scale and phenomenal for the time professionalism. Ancient miners showed particular
interest in the gold-bearing placers of the Kraishte area as evidenced by a number of preserved artefacts including old
diggings, heaps of sorted river materials, water-supply structures, etc. (Konyarov, 1953). Mining in the area has
considerably disturbed the natural distribution patterns of placer gold with respect to its content, grain size and morphology.
Ancient geologists established and sampled even the smallest surfacial ore materializations (Georgiev, 1987) without
knowing the contemporary methods of investigation and analysis. A good example for their professionalism are the
metasomatites from Central Bulgaria containing Au up to 200 ppm. Present investigations show that Au in them is not
presented by own minerals (Tsintsov, unpublished data) but even though its high concentrations were proved and industrial
exploitation began through the so called “rupi” i.e. surfacial excavations.
Gold is the major component in the placer deposits in Bulgaria but it is not studied enough yet despite all the investigations
carried out during a long period of time. According to different researchers (Konyarov, 1953) the reason for this is that it
was extracted already in the past and is no longer of industrial interest. The investigations on placer deposits mainly have to
clear out the strength characteristics of the sediments in terms of their constructional use. The great interest to gold
worldwide in the 80’s led to reestimation of the deposits considered as non-industrial earlier. Possibilities for accompanying
gold extraction at the process of inert materials production were surveyed in Bulgaria. Most of the golden articles were
found during this exploration.
Field sampling of the alluvial deposits was done through specially constructed sluices, installed to the wash appliances for
inert materials extraction (Tsintsov, 1994). This allowed the mechanized processing of heaps of sample materials which in
some particular cases reached to n.103 m3. The obtained concentrates were reduced to 15-20 l by hand pan-off devices
and then they were sifted out by laboratory sieves to three fractions - +2.5 mm, 2.5-1.0 mm and -1.0 mm. Each of these
fractions went through magnetic separation and only the non-magnetic fractions were analysed under binocular
stereomicroscope. The laboratory studies referring the sacrificial structure and the metal hallmark were done on the
surfaces of the finds. Polished preparation of earlier studied articles helped to determine more precisely the hallmark and
the distribution character of the elements in their volume. The electron microprobe analyses were done by scanning electron
microscope SEM Phillips - 515, equipped with analytical system EDAX 9100 (Tsintsov and Damyanov, 1994).
Interesting feature of the alluvial sediments in West Bulgaria is the presence of “white gold” in them (Konstantinov, 1949).
According to the author mentioned the ancient miners avoided these grains. Later they began digging them after
understanding that these were Au-amalgams. Contemporary miners also have negative attitude but only to some of the
“white gold” grains. According to them a reliable method for removing the undesired grains is by heating - the grains which
remain white “spoil” the extracted metal at melting and they should be taken out. It is known that the placer gold from these
deposits was object of industrial production in the past and it was recovered through amalgamation in most of the cases
(Konyarov, 1953; Velkov, 1972). This resulted in Hg polluted river sand washes all over the region with some of the
formed Au-amalgams remaining in them. It is difficult to accept that the amalgams impeded the miners to recover and
process the metal which again provokes the interest to the mineral character of the problematic grains.
For the first time articles of an ancient culture were found in concentrates recovered from the recent alluvium (Q5) of
Struma river on the territory of Kraishte area (part of West Bulgaria, north from Pastuh village) (Tsintsov, 1992). The
deposits are dynamic fluvial sediments of the channel type consisting mostly (up to 70-75 %) of fine to medium-grained
sand mixed with silt and clay as well as cobbles in the 80-100 mm size range. The golden articles found were small washer-
like ringlets and pierced discs of 1.8 to 3.2 mm outer diameters and an average thickness of 0,8 mm. The concentrates,
examined under binocular stereomicroscope, showed the presence of separate fine fragments of golden articles and a very
small amount of gold balls of diameters in the range 0.01 to 0.13 mm. In order to study the distribution of these articles in
the area, new samples of channel deposits at a distance of about 130 to 150 m upstream were taken and examined. The
concentrates yielded numerous gold articles resembling the first finds in shape and size. There were much more gold balls,
the largest reaching 0.30 mm in diameter. The next sampling was made in analogous deposits, upstream, at a distance of
about 1.6 to 1.8 km from the first find. A total absence of any archaeological objects was observed. The analysis of these
results directed the exploration to deposits in the valley consisting largely of coarse clastic, unsorted materials. Such debris
fill the valley between the last two sampled sites at a distance of about 600 to 700 m from the first find. In addition to the
numerous washer-like objects, the samples taken contained ribbons of pure gold wound in the form of helices. Some 20-
25 m from the placer where the helices were found, the concentrate yielded several gold bears of various size. In all these
samples there were also gold balls much larger than these in the first find, their maximum diameters reaching 1.8-2.0 mm.
The field exploration done in 15 years shows that the alluvial deposits in West Bulgaria developed for gold extraction in the
past contain gold artefacts. As a result over five thousand articles were found in 12 independent from one another deposits
situated in sediments of the rivers Struma, Ogosta, Iskar, Palakaria, Kopriven, German, Dragovishtitsa, Uineshtitsa,
Topolnitsa, Zlatitsa and others. Objects made of some other metals are found very rarely - some silver wires and two
Roman bronze coins in the region of Kraishte. Certain difference in the morphology and the finding conditions of the articles
from SW Bulgaria (rivers Struma, Palakaria, Dragovishtitsa, German, Kopriven, Uineshtitsa and others) and the ones from
NW Bulgaria (rivers Ogosta and Zlatitsa) is established.
Golden articles from SW Bulgaria are presented by flat washer-like ringlets, cylindrical beads, biconic beads, plates,
helicoidal ribbons, hollow prisms, nails and others. Flat washer-like ringlets and cylindrical beads with dimensions from 1
mm to 12 mm are predominating. The biggest find is a helicoidal ribbon and it reaches length of 21 mm. Millions of small
gold balls are found everywhere. Most of them are with spherical, rarely with drop-like form and of diameter from 6 *m to
3.0 mm. A common feature of all golden artefacts is their pure stylistic form and precise make. Their surfaces are golden
colored, weakly dulled, rarely covered by dark-red crusts of the mechanically deposited Fe-hydroxides. The SEM studies
of the surfaces of some articles show the presence of multilayered structures and signs of gold recrystallization. The finds
are often accompanied by Hg and some of them are amalgamed. In these cases they look like iron objects but after heating
at spirit lamp they become golden colored again. Local surfacial analyses show that most of them have a relatively high
hallmark - >85.0 at % Au and for most of the articles these results are proved for the inside parts as well. According to the
electron microprobe analyses the admixtures are of Ag (up to 15.0 at %) and Cu (up to 2.0 at %), relatively uniformly
distributed in the volume of the finds, which gives reason to assume that they were made by casting. The deformations are a
result of the mechanical influences of the harder objects on them during the exogenic transport in the river. With respect to
their distribution in the placer, the degree of mechanical wear and other characteristics, the archaeological objects resemble
the native gold grains from alluvial placers. The original shape is better preserved in the smaller articles (ringlets and pierced
discs) than in the larger ones (beads and helicoidal ribbons). This is not accidental in view of the fact that in an actively
developing placer the smaller gold grains sink deeper into the deposit where they are better protected from the abrasive
action of the harder minerals. According to Petrovskaya (1973), the processes of recrystallization of gold under supergene
conditions are accompanied by almost total removal of silver from the grain surfaces which results in high hallmark of the
outer layers. It may well be that analogous processes have largely contributed to the increased hallmark of part of the finds.
More, the crystallization structures on the surfacial layer of some of them evidence that their insignificant transport in the
deposit was accompanied by continuous depositions in intermediate collectors. Because of the direct relationship between
the size of gold grains and the distance at which they are transported by the stream, a number of authors are of the opinion
that gold in the free state forms mostly autochthonous placer deposits in the immediate vicinity of the source. Thus, it may
be assumed that the archaeological site, which fed the Recent Kraishte alluvium with golden articles, is very close to the
place where the larger objects were found.
Golden articles from NW Bulgaria are more various in forms that the latter. They are presented by flat washer-like ringlets,
cylindrical and biconic beads, wires with circle or flat section in different forms, plates, parts of earrings (?), nails, etc (Fig.
2). Some of them are strongly deformed during the exogenic transport in the deposit, but still traces of polishing appear on
the surface of some finds. Amalgamed or polluted with Fe-hydroxides areas are not observed. Gold hallmark is over 65.0
at % and Ag is the only admixture. Gold balls are fewer than the ones from SW Bulgaria and their dimensions reach up to
5.0 mm. Articles resembling the latter ones are rarely found and they are presented mainly by flat washer-like ringlets and
cylindrical beads, rarely by helicoidal ribbons.
The presence of the golden artefacts in the alluvial sediments most probably is a result of erosive processes in the terraces
on which archaeological sites are situated. It is difficult to determine the type of the archaeological sites but the great
number of small gold spheres suggest that these were ancient workshops for processing gold. According to Pernicka
(1994) all technical conditions for gold casting were available even at the end of Vth mill. cal. BC. In the period Vth-Ist
mill. cal. BC gold extraction on the territory of present West Bulgaria most probably was accompanied by its processing
and the wokshops were built in the immediate vicinity of the gold deposits.
According to Pernicka (1994) workshops in the past were most often situated geografically near to the deposits but there
are exceptions as well. That is why the relation should be proved analytically. This can be done through comparison of the
ratios from the Pb isotope analysis in the archaeological metals and the primary metal of which they are made (Brill and
Wampler, 1965). For greater reliability of the possible relation, it is expedient the mentioned analysis to be combined with
analysis of the microelemental composition (Pernicka, 1994). Obviously the analyses in the particular case should be done
with very precise apparatuses in order to minimize the destroyed quantities.
The invasion of the Doric tribes (Ist mill. cal. BC) arouses significant ethnic changes on the Balkan peninsula (Velkov,
1972). Spiritual and material centres of the civilization of that time were grabbed and destroyed. It is possible that the gold
workshops were also destroyed then and their traces on the ground were completely covered up by the nature which can
explain the lack of information for them in the later historical documents.
In 1972 Varna Chalcolithic necropolis was found out which had not analogue in the other parts of the country. It is referred
to the end of IVth mill. cal. BC, accepted mainly as a period in which extraction and processing of Cu were developed in
the Bulgarian lands. Thus, some scientists presumed that the treasury was not worked out in Bulgaria. According to them it
is left near Varna city by a people that was passing by. The presence of Pt in some articles supported this hypothesis as
gold with such composition was not established in Bulgaria (Hartmann, 1978). Later Weisgerber and Pernicka (1995)
made a guess that gold with the mentioned admixtures existed. Contemporary investigations of heavy minerals concentrates
from sediments of SW Bulgaria show that they contain certain quantity of small grains of platinum-group minerals (Tsintsov
and Damyanov, 1994; Tsintsov, 1998). Some of them were most probably recovered with gold even in the past and they
were notoriously called “white gold”. Sperrylite (PtAs2) is the most often met mineral (Tsintsov and Damyanov, 1994).
Presumably ancient miners could not remove these grains out before melting the gold. Chemical analyses of the placer gold
from SW Bulgaria prove admixtures of some platinum-group elements (PGE) in its composition - mainly Pt (10-30 ppm)
and rarely Os (1-3 ppm) (Tsintsov, unpublished data). It may be assumed of all these facts that the gold from placer
deposits in Bulgaria which was recovered and processed in the ancient times contained some quantities of PGE.
Alluvial treasuries in West Bulgaria show that this territory was centre both for extracting and processing gold in the past.
Their close location to Varna Chalcolithic necropolis and the quite similarity of some finds in terms of form prompt to a
relation between them in the time (Tsintsov, 1992). The peculiarities of the alluvial finds probably outline a long period of
time while the ones from Varna fix certain ages. Do they have a point of intersection in the time and where is it if the answer
is yes? Should we look for it as it is a question not only of gold but of the oldest gold (Varna necropolis) ever processed by
people. The alluvial finds are familiar only to few specialists for the time being. Anyway, the glamour and the mystery of the
treasuries discovered provoke the interest not only to archaeology but also to the potentials of the contemporary science.
How were these articles observed and what technics were used at their processing (especially for the ones with dimensions
of 1-2 mm)? What is their relation with the placer gold from the deposits where they are found? What is the origin of Hg
and what is its function? These are some of the questions waiting for answers. Obviously their settling would help to
understand more about the civilization that was living in the Bulgarian lands and has reached such perfection in the
development of its material culture. It would probably give more information about Varna necropolis as well. Along these
lines the factual material was collected. Now the most difficult part of the study remains - the analytical investigations and
the interpretation of the results.
BRILL, K., WAMPLER, J. (1965): Isotope ratios in archaeological objects of lead. - In: Young (ed): Application of
science in the examination of works of art, Boston, 155-166.
HARTMANN, A. (1978): Ergebnisse der spektralanalytischen Untersuchung aneolithischer Goldfunde aus Bulgarien. -
Studia Praehistorica 1-2; 27-45.
KONSTANTINOV, M. (1949). Old native gold mining in Kraiste. – Minno delo, 4, 81-84 (in Bulgarian).
KONYAROV, G. (1953): Contribution to Mining and Metallurgy History in Bulgaria. - BAS, Sofia, 160 pp. ( in
MARFUNIN, A. (1987): History of Gold. - Nauka, Moskow, 246 pp. (in Russian).
PERNICKA, E. (1994): Status of the Natural Science Studies on the Most Ancient Metals. - In: Todorova, H., Popov, P.
(eds): Problems of the Earliest Metallurgy, MGU, Sofia, 14-89 (in Bulgarian).
PETROVSKAYA, N. (1973): Native Gold. - Nauka, Moskow, 348 pp. (in Russian).
TSINTSOV, Z. (1992): Unique finds of golden articles in alluvial placers. - C. R. Acad. bulg. Sci., 45, 6; 59-61.
TSINTSOV, Z. (1994): Sampling of sediments for minerals belonging to the platinum group. - Minno Delo I Geologia, 11,
32-35 (in Bulgarian, with English summary).
TSINTSOV, Z. (1998): Composition, distribution and transportation of platinum-group minerals in alluvial sediments of
Blagoevgrad graben. - Review of the Bulgarian Geological Society, 59, 2, 59-65 (in Bulgarian, with English summary).
TSINTSOV, Z., DAMYANOV, Z. (1994): Sperrylite from Struma River alluvial placers, Blagoevgrad graben, SW
Bulgaria. - N. Jb. Miner. Mh. H 11; 518-528.
VELKOV, V. (1972). Ore Mining in Ancient Thrace. - Annual of the National Politechnic Museum, 2; 23-38 (in
WEISGERBER, G., PERNICKA, E. (1995): Ore mining in Prehistoric Europe: an overview. - In: Morteani, G.,
Northover J. (eds): Prehistoric Gold in Europe, 159-182. Proceedings of the NATO Advanced Research Workshop on
Prehistoric Gold in Europe, Seeon, Germany, September 27 - October 1, 1993.
|Eurasian Prehistoric Studies. Section: 85th Birth Anniversary of Eugen Comşa
ed. by Lolita Nikolova and Alexandra Comsa, RPRP 8 (2008-2010) online (Contents)