• Stone technology Lítica

    Stone is the oldest known material used for tool making during the course of human development. This does not mean that it was the only material used, but its greater durability compared to wood and bone has left it better preserved in archaeological sites.

    The first stone tools were simple axes and knives made in Africa, Europe, and Asia during the earliest period of prehistory, known as the Paleolithic (from paleo = ancient and lithos = stone), around two million years ago. The first humans reached the Americas approximately 20,000 years ago, bringing with them a suite of stone tools such as axes, lance heads, knives, and scrapers, which they used for hunting, butchering, preparing skins, and even for making other tools.

    Several different types of rock were used to make tools, with rocks with specific properties used for different purposes. Crystalline rocks are relatively easy to break and so could be readily shaped into tools with sharp cutting edges; volcanic glass has similar properties. In contrast, as granite and sandstone fracture in an irregular and unpredictable way without leaving sharp edges, they cannot be shaped into cutting tools but were useful as hammers and crushers, as grinding tools such as mortars and pestles, and for polishing; they were also used to make stone containers. Carved or polished rocks were not only used as tools or utensils; in more recent times they were used to make sculptures.

    The techniques used for polishing stone emerged in the Old World during the Neolithic period (from the Greek neo = new and lithos = stone), approximately 12,000 years ago. Similar techniques arose in the Americas around 10,000 years ago among hunter gatherer groups that developed techniques to grind wood and bone and mortars to grind pigments and food, as well as techniques for making stone figures. Later, around 4000 years ago, grinding tools such as mortars and pestles began to be used by the continent’s first agricultural communities.

  • Knapped stone

    Tallado en piedra de una punta de dardo o flecha
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    Stone carving or knapping is the oldest human technology in the archaeological record. It began to appear one to two million years ago, when the first humans began using simple stones as hammers and cutting tools, modifying their natural shape by striking them against each other to produce angular, sharp-edged tools. Over time their skills improved and new techniques were developed to work stone into useful items. Image 1

    Rocks are found in almost all natural environments, but not all are equally suitable for tool making. The most widely used were crystalline rocks such as quartz, chert, and flint, and volcanic glasses, as striking or pressuring these produced predictable fractures that allowed tools to be shaped. Imagen 2

    Once a knapper selected a nodule of suitable rock, he removed the outer layer, which is normally rough from its exposure to the elements. The smooth, regular interior of a single nodule could then be worked into several tools. Knapping is a complex process that requires careful planning, as each blow can be made only once and errors can have a major effect on the finished piece, even rendering it unusable and forcing the knapper to start over again.

    Depending on the tool being made, the knapper faced a series of decisions as he worked a core of stone. Some solid objects, such as large hammers, were made by chipping off small flakes of the outer layer of the nodule, giving shape to the inner core. Thin cutting tools such as knives were made by working on chips struck off the core with sharp blows. These thin, sharp slices of rock are known as flakes.

    Flakes of flint or similar rock could be used unworked as long as their edges were kept sharp, or could be knapped into more complex pieces such as arrowheads or knives. Modifications made to these flakes included serrated edges and blunt edges, which allowed them to be held in the hand or inserted into a handle. Tools that had lost their cutting edge could also be reworked to make them sharp again.

    Knappers would often strike the rock they were working on directly, using a harder pebble. This would guarantee that the piece would break, but an intense blow would reduce the craftsman’s control over the line of fracture, rendering the process unpredictable. By using softer strikers made from wood, bone, or antler, the force of the blow could be reduced and the knapper could exert more control over how the workpiece would break.

    When greater precision was required, the knapper used an intermediate tool rather like a chisel, which would transmit the force of the blow through to the workpiece, cushioning the impact or directing it to a specific point. This knapping technique is called soft-hammer percussion.

    The way in which the workpiece was held would also affect the result of the knapping process, so knappers could vary the outcome by choosing to hold the piece in their hands, rest it on part of their body, or place it on a stone or wooden anvil.

    The finishing elements of the design, such as notches and serrated edges, required the removal of tiny, regular flakes from the edges of the tool. This stage of tool making was critical, as a single ill-placed blow could destroy the entire piece. For this reason the final stage was undertaken using pressure rather than striking, with the knapper exerting a strong, constant pressure until a flake gave way as desired.

    One form of knapping, known as monofacial reduction, created tools by working only one side of the workpiece. This technique required the knapper to strike the naturally flat face of the flake, aiming to remove chips from the other side. In profile, monofacial pieces are asymmetrical, with one flat face and one convex face. Bifacial reduction, in contrast, is a technique in which the knapper works on the entire surface of a piece on both sides, leaving a tool with no flat side. In profile view, both sides of bifacial pieces are convex.

    Stone knapping has been used to make cutting, scraping, and perforating tools in the Americas since the earliest human times, and is still used by some indigenous groups.

    A few selected examples help show the quality of stoneworking among the ancient peoples of the Americas. Around 4000 BCE, fishermen on the north coast of present-day Chile worked huge and very thin bifacial blades up to 30cm (12 inches) long, from lustrous white, yellow, and red fine-grained silica. These tools, apparently used as knives, were greatly valued and were left as grave goods. Around the year 500 CE in Mesoamerica, workmen took advantage of the region’s high quality obsidian to create very thin and sharp pieces, with extremely fine cutting edges. The Aztecs of around 1400 CE created the so-called “eccentric flints”, blades crafted with great precision from flint or obsidian in shapes of spirals or waves, which were used as ceremonial sacrificial knives and were also buried as temple offerings. Images 3, 4, 5

  • Polished stone

    Stone polishing takes advantage of the qualities of coarse-grained, porous rocks such as granite and sandstone, grinding them into the desired shape. If the shape of the selected rock must be changed significantly, it is first worked with blows from a hard hammer, generally another stone of equal or greater hardness. The surfaces of the workpiece are then patiently worn down by rubbing them against a rough surface such as another porous stone. Image 1

    In the case of implements used for grinding or milling grain, the stone used as a recipient for the grain and the stone used for grinding are selected for their natural shape. Sometimes the stone is already suitable for the required function, and little work is needed to give it the right shape. With time and usage, the action of grinding–the constant blows between the pestle and the mortar, as well as friction between the two– gradually makes the mortar more hollow. Images 2, 3

    Objects made from polished or worn stone are characteristic of agricultural societies. Such artifacts consist mainly of stone basins coupled with pestles made from wood or stone. Others, such as conanas or quern grinders, consist of an elongated concave stone over which a smaller stone called a handstone was rolled. Other polished stone pieces include stones with holes bored through them, which were used as hammerheads as weights for fishing nets, or as digging tools, among other uses.

    Larger and more complex items were also made from polished stone. Around the year 1200 CE in the territory of modern-day Costa Rica, intricate designs were engraved on stones by wearing down and polishing the surface. Such artifacts include seats, containers, and mortars with ornately decorated pedestals.

    The art of sculpture become highly developed in prehistoric Mesoamerica. Sculpted works included large pieces made from basalt and granite, representing gods or members of the nobility, and made reference to historic and/or religious events. From the year 1000 BCE onwards, the Olmec group carved large blocks of basalt into the shapes of faces. These are the “colossal heads” up to three meters (ten feet) in height that represented major chieftains of that ethnicity. Later, around the year 500 CE, the Mayas sculpted large rectangular slabs of stone known as stelae or tetun. Onto these slabs they carved drawings and texts in Mayan glyphs, as well as ceremonial scenes and historic events.

    In the Andean region sculpture also reached a high degree of artistic expression. One of the best examples comes from the Tiwanuku culture, which existed in the Altiplano of modern-day Bolivia between from 100 to 1100 CE. Statues, some situated inside temples such as the Bennett and Ponce monoliths, others located nearby like the famous Gateway of the Sun, were made by expert craftsmen skilled in carving and polishing huge stones and recording on them a significant part of the group’s beliefs.

  • Lapidary

    Lapidary is the term used to refer to the set of techniques used to work precious stones. As each culture chooses the materials that it considers beautiful and valuable, throughout the world ornaments, jewels, and ritual items have been made from a wide range of raw materials.

    Lapidary began at the sites of early mining activities, which in the Americas this activity began in what is now northern Chile around 9000 years ago. Often the first stones considered precious were bright green and blue copper minerals such as malachite and chrysocolla. Later additions included jade, jadeite, nephrite, and other grey-green stones; amber, the fossilized resin of trees, with its intense yellow color; chalcedony, a white rock crystal; and turquoise, a light green mineral. Obsidian, a translucent black volcanic glass, has also been widely used in creating stone tools and was sometimes treated as a precious stone.

    The use of precious stones and the skills required to transform them into special objects emerged particularly in societies that began to manifest social distinctions, with jewels and elaborately decorated ceremonial objects more commonly found in groups that have chiefs, priests, kings, or other high-status individuals able to obtain scarce raw materials and commission expert craftsmen to work them.

    Quartz, emerald, and turquoise were prized throughout the Americas for their luster, colorfulness, and comparative rarity; these properties gave them special value and were often associated with divine qualities. Lustrous black stones such as obsidian and some iron-rich minerals were also highly valued by several groups for their reflective properties when polished. This led both the Chavín people (Central Andes, 1000 BCE) and the Aztecs and their predecessors (from around 1000 CE) to use them as mirrors. Image 1

    From the times of the Olmecs, beginning around 1000 BCE, jade was also highly prized as a raw material, and used to craft personal ornaments for leaders and buried as offerings in temples and as grave goods of important figures. Figurines, adornments, and plates of jade were also made by the Mayas and the Aztecs, to whom jade was so precious it was worth more than gold. Image 2

  • References

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