• Location: Brehov, Slovakia
• Weight: 23.3g
• Dimensions: 3.6 x 3.2 x 1.6 cm
• DETAILED DESCRIPTION

Obsidian from Eastern Slovakia General Characteristics 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 grey or red. It is usually opaque, but its transparency increases as the iron oxide content decreases. History The occurrence of obsidian in Slovakia is relatively limited compared to other local neovolcanics. 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, mainly composed of rhyolite. Nests of obsidian nodules, mistakenly called heaps by collectors, are usually found in rhyolitic tuffs, from where it has often eroded as a more resistant material, and thus 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 led to obsidians having a higher SiO2 content and 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 ranges between 0.19 and 0.31%. The density ranges between 2.3 and 2.4 g/cm³. Porosity is well below 1%, and hardness is between 5 and 5.5 on the Mohs scale. Local obsidian is transparent. Depending on the chemical composition, its colours vary from black, grey, bluish, and greenish, sometimes with silvery reflections. No other obsidian in the world offers such a colour spectrum! Curiosities / Potential By a strange coincidence, the occurrence of obsidian in Slovakia dates back 15,000,000 years, roughly around the same time as its Czech "sibling", moldavite, with which it is often compared due to its appearance, and at a certain distance and under the right light, they are indistinguishable. But of course, upon closer inspection, the differences are clear, and there can be no confusion. Interest in obsidians in general is growing both in Europe and worldwide. Slovakian ones are valued for their rare occurrence, limited quantity, unique colour, and the aforementioned resemblance to moldavites. Its current low price makes it an ideal investment stone for the future. Obsidian is easy to work with and polish, and as a raw material, it is truly suitable for jewellery purposes. It is also used to make replicas of Paleolithic cutting tools, stone beads, and jewellery. 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 colour is black or blackish-grey. Cut stones achieve a high lustre, and the cutting yield is comparable to coloured commercial 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. Due to its easy workability, it is also suitable for carving small figures, 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 thanks to tektites, others are also mentioned alongside 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 jewellery, the dominant stone of which was Eastern Slovak obsidian. Requests 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 cutting tools essential in the daily life of prehistoric peoples. Jewellery and decorative objects: Due to its lustre and aesthetic properties, Slovak obsidian is a highly valued material for making jewellery and decorative objects: Necklaces, bracelets, rings: Obsidian is often used in jewellery production. Amulets and talismans: Due to its beauty and supposed protective properties, obsidian is often crafted 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 supposed abilities to promote emotional healing and balance. Collecting: Mineral collections: Obsidian is popular among collectors of minerals and gemstones 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: Sculpting and carving: Artists use obsidian to create detailed sculptures and carvings due to its ability to be finely worked.