• Location: Brehov, Slovakia
• Weight: 8.7g
• Size: 3.1 x 2.1 x 1.1 cm
• DETAILED DESCRIPTION

Obsidian from Eastern Slovakia General information Obsidian is a type of volcanic glass, a rock that forms as a result of magmatic activity when hot lava rapidly comes into contact with a cold environment and then quickly solidifies. The rock is very rich in siliceous compounds and is a natural form of glass. It is typically dark, ranging from black to gray or red. It is usually opaque, but its transparency increases as the iron oxide content decreases. History The presence of obsidian in Slovakia is relatively limited compared to other local neovolcanic areas. Our ancestors used it to make cutting tools as early as the Paleolithic (2,500,000 years ago), but it has been shown that these tools were also used during the Neolithic (5,000 years ago). In Europe, primary occurrences of obsidian suitable for the production of cutting tools are limited, mainly scrapers, spearheads or knives. From the results of ongoing research, it is clear that the importance of Eastern Slovak obsidian as a raw material for the production of chipped tools far exceeded its local significance. Therefore, Eastern Slovak obsidian was distributed throughout Central and Eastern Europe and the Balkans as far as the Mediterranean. A bit of chemistry Obsidian is the product of highly acidic lavas from Neogene volcanism. Its origin is closely linked to rhyolitic volcanism. Its occurrences form the peripheral parts of larger volcanic bodies, composed mainly of rhyolite. Nests of obsidian nodules, mistakenly called heaps by collectors, are usually found in rhyolitic tuffs, from where it often eroded as a more resistant material, and so today its shape and surface often resemble Bohemian moldavite. Eastern Slovak obsidian belongs to a group of unaltered acidic volcanic glasses with a silica (SiO2) content of approximately 80%. The higher acidity of local lavas has resulted in obsidians having a higher SiO2 content and a lower water content than the world average. This is the reason for their greater durability and suitability for the production of chipped tools. The water content of obsidian is unusually low. The H2O content varies between 0.19 and 0.31%. The density varies between 2.3 and 2.4 g/cm³. Porosity is well below 1%, and the hardness is between 5 and 5.5 on the Mohs scale. Local obsidian is transparent. Depending on the chemical composition, its colors range from black, gray, bluish, and greenish, sometimes with silvery reflections. No other obsidian in the world offers such a color spectrum! Curiosities / Potential By a strange coincidence, the presence of obsidian in Slovakia dates back 15,000,000 years, more or less the same period as its Czech "brother", moldavite, with which it is often compared for its appearance, and at a certain distance and under the right light they are indistinguishable. But of course, on closer inspection, the differences are clear and there can be no confusion. Interest in obsidians in general is growing both in Europe and worldwide. Slovak ones are valued for their rare presence, limited quantity, unique color, and the aforementioned similarity to moldavites. Its current low price makes it an ideal investment stone for the future. Obsidian is easy to work and polish, and as a raw material it is truly suitable for jewelry purposes. It is also used to make replicas of Paleolithic cutting tools, stone beads, and jewelry. Obsidian can be collected at individual sites in the form of small boulders from 1 to about 20 cm in diameter. However, most nodules are between 1 and 5 cm. Their predominant color is black or blackish gray. Cut stones achieve a high luster and the cutting yield is comparable to commercial colored chalcedony. It can be used not only in the form of simple cabochon or table cuts, but since it is transparent, it can also be faceted. Faceted stones are very spectacular and surpass dark gneisses and morions in appearance. Thanks to its easy workability, it is also suitable for carving small figures, the so-called glyptics. In any case, it deserves to be promoted as one of the very interesting materials used since the Stone Age. Although interest in natural glass is growing mainly due to tektites, others are also mentioned along with them. The scientific community has organized several conferences dedicated to natural glass research. In 1987, one of them was held under the auspices of Charles University in Prague. For this conference, the Granat cooperative from Turnov produced silver jewelry, the dominant stone of which was Eastern Slovak obsidian. Inquiries and orders from abroad continued for several years. Uses of obsidian Obsidian has a wide range of uses due to its physical properties and aesthetic qualities. Tools: Historically, obsidian was widely used for the production of various tools and weapons, especially in prehistoric times. The sharp edges of obsidian were ideal for making: Arrowheads and spearheads: Due to its hardness and sharpness, obsidian was an ideal material for arrowheads and spearheads Knives and scrapers: It was used to make essential cutting tools in the daily life of prehistoric peoples Jewelry and decorative objects: Due to its luster and aesthetic properties, Slovak obsidian is a highly valued material for making jewelry and decorative objects: Necklaces, bracelets, rings: Obsidian is often used in the production of jewelry Amulets and talismans: Due to its beauty and presumed protective properties, obsidian is often made into amulets and talismans Decorative objects and figurines: Handcrafted decorative objects and figurines made of obsidian are appreciated for their aesthetic and artistic qualities Healing and esotericism: Obsidian is often associated with various spiritual and therapeutic practices: Protective properties: Obsidian is believed to have the ability to ward off negative energy and protect the wearer from psychic attacks Healing: In alternative medicine, obsidian is used for its presumed abilities to promote emotional healing and balance Collecting: Mineral collections: Obsidian is popular among mineral and gemstone collectors who appreciate its unique properties and appearance Modern medicine: Surgical scalpels: Although less common, some surgical scalpels are made of obsidian as its extremely sharp edges allow for very precise cuts Sculpture: Sculpture and carving: Artists use obsidian to create detailed sculptures and carvings due to its ability to be finely worked