P hysical Characteristics: Color is amber yellow to orange. Luster is resinous. Transparency: Transparent to translucent. Crystal System does not apply because amber is amorphous meaning it does not have an ordered structure. Habits include nodules embedded in shales or sandstones and those that are washed up on beaches. Fracture is conchoidal. Specific Gravity is approximately 1. Streak is white. Other Characteristics: Can be burned, fluorescent under UV light and is much tougher will not crumble as easily than modern tree resins.
Best Field Indicators are color, density, toughness, softness and trapped insects. Amber is the fossilized resin from ancient forests.
Amber is not produced from tree sap, but rather from plant resin. This aromatic resin can drip from and ooze down trees, as well as fill internal fissures, trapping debris such as seeds, leaves, feathers and insects. The resin becomes buried and fossilized through a natural polymerization of the original organic compounds. Amber is a fossilized resin, not tree sap. Sap is the fluid that circulates through a plant's vascular system, while resin is the semi-solid amorphous organic substance secreted in pockets and canals through epithelial cells of the plant.
Land plant resins are complex mixtures of mono-, sesqui-, di-, and triterpenoids, which have structures based on linked isoprene C5H8 units Langenheim, , p. Volatile terpenoid fractions in resins evaporate and dissipate under natural forest conditions, leaving nonvolatile terpenoid fractions to become fossilized if they are stable enough to withstand degradation and depositional conditions. The fossil resin becomes incorporated into sediments and soils, which over millions of years change into rock such as shale and sandstone.
Therefore, amber is formed as a result of the fossilization of resin that that takes millions of years and involves a progressive oxidation and polymerization of the original organic compounds, oxygenated hydrocarbons. Although a specific time interval has not been established for this process, the majority of amber is found within Cretaceous and Tertiary sedimentary rocks approximately million years old Although there are contrasting views as to why resin is produced, it is a plant's protection mechanism.
The resin may be produced to protect the tree from disease and injury inflicted by insects and fungi. Resin may be exuded to heal a wound such as a broken branch, and resins possess odors or tastes that both attract and repel insects Langenheim, , p. In mature trees, resin may simply exude from vertical fissures in the bark due to tension produced by rapid growth Langenheim, , p. Resin may also be produced as a plant's method for disposing of excess acetate.
There is no one tree responsible for the resin that fossilizes into amber. Botanical affinities have been suggested based on examination of the entombed debris and through chemical studies of the resin. The botanical affinity of jelinite, Kansas amber, appears to be from the Araucariaceae family, which is considered to be a primary Mesozoic amber tree.
Although this tree does not exist today in the northern hemisphere, it would closely resemble Agathis australis, or the huge Kauri pine found today in New Zealand. During most of the Mesozoic geologic time period, gymnosperms dominated land vegetation. Some of the amber land plants were probably conifers from the order Pinales, in the families: Araucariaceae e. One depositional environment for amber is marginal marine.
Amber's specific gravity is slightly over 1 and it floats in saltwater; therefore amber becomes concentrated in estuarine or marine deposits, moved some distance from the original site Langenheim, , p. Trees and resin may be transported and deposited in quiet water sediments that formed the bottom of a lagoon or delta at the margin of a sea. Wood and resin are buried under the sediment and while the resin becomes amber, the wood becomes lignite.
Wet sediments of clay and sand preserve the resin well because they are devoid of oxygen. Therefore, given copious resin producing trees and appropriate burial conditions, amber is preserved in sedimentary clay, shale, and sandstones associated with layers of lignite, a woody brown coal.
A generalized interpretation of the depositional conditions present in Kansas amber-bearing strata is that a transgressing or advancing Cretaceous sea in north-central Kansas led to deposition and preservation of fluvial, estuarine, and lagoon or bay deposits behind a barrier island system Types of Amber One method of classifying amber is by color and degree of transparency. This criteria correlates to an optical classification of amber varieties.
Colors of amber include yellow, orange, red, white, brown, green, bluish, and "black" dark shades of other colors.
The degree of transparency varies in amber from clear to cloudy. Clear amber is transparent and usually ranges from pale yellow to dark reddish yellow.
Cloudy amber can be semi-transparent to opaque, a variety of colors and separated into terms such as fatty, bone or osseous or foamy or frothy. Fatty amber does not necessarily imply a green color. Fatty amber has tiny bubbles, suspended dust particles, and is usually a translucent, yellowish color resembling goose fat or also compared with the look of whipped honey. Green amber has tiny bubble inclusions and suspended particles, but it does not have the yellowish appearance of fat.
The green color probably results from decaying organic matter in a marsh environment. Bone or osseous amber is whitish yellow or brown in color, opaque and looks similar to ivory or bone. Black decayed organic debris is commonly found in this type of amber. Foamy or frothy amber is very soft and therefore incapable of taking a polish. It is opaque and usually contains pyrite infilling cracks.
Natural lumps of amber formed from resin extruded inside and outside the tree trunk. These forms create external drippings and swellings, as well as internal resin which gathers in fissures inside the tree trunk.
Internal crack fillings 2. Forms under the bark 3. Resin pocket in the wood 4. Forms between the bark 5. Fillings from tree wounds 6. External stalactite shapes 7. Stalactite 8. External drops and swellings This was taken from Lausitzer Bernstein by B. Kosmowska-Ceranowicz, et. Other descriptive names for amber exist, reflecting not only color and degree of transparency but also chemical composition, the degree of weathering, places of discovery, workability, and functions in folk rituals.
In Poland, some folk names are applied to amber and some 80 variety names. Another mode of classifying amber, a physical classification, is based on procurement, land or sea.
Sea stone and scoopstone refers to amber found in or near the sea. Scoopstone is the amber gathered from seaweed. Sea stone or sea amber is collected as it is washed onto the beach or directly from the water amber floats in salt water. This static electricity was believed to be a unique property of amber until the sixteenth century, when English scientist William Gilbert demonstrated that it was characteristic of numerous materials. He called it electrification, after elektron, the Greek word for amber.
In the Western Hemisphere, the Aztecs and Mayans carved amber and burned it as incense. The decorative use of amber culminated in with the completion of an entire banquet room made of amber panels constructed for King Frederick I of Prussia. In the nineteenth century amber attained new significance when German scientists began studying the fossils imbedded in it. Resins are complex substances that include oily compounds called terpenes.
Over time, some terpenes evaporate while others condense and become cross-linked to each other, forming hard polymers. However, different species of trees produce different types and amounts of resins. The exact structure and composition of amber depends on the makeup of the original tree resin, the age of the amber, the environment in which it was deposited, and the thermal conditions and geological forces to which it was exposed. Thus, even amber obtained from similar locations may vary in chemical structure and physical characteristics.
Although deposits of amber occur throughout the world, amber from the coast of the Baltic Sea is the best-known. It is called succinite amber because it contains a substantial amount of succinic acid.
Most Baltic amber came from pine tree resin. Amber that lacks succinic acid is classified as retinite amber. Amber from Mexico and the Dominican Republic began forming million years ago from the resins of extinct species of Hymenaea or algarrobo trees. These flowering trees thrived in the canopy of extensive tropical rain forests. They produced copious amounts of resin that eventually hardened into amber. Torrential rains washed the amber to deltas where it was covered with silt.
As sea levels changed, the amber settled on the sea floor and the sediment over it hardened into rock. Later, mountain formation pushed up the rocks. Many components of amber are similar to those of modern resins. However the cross-linking of these compounds makes the amber hard, with a high melting point and low solubility. Amber has a hardness of on Mohs's scale, the standard for minerals and gems. On this scale, talc is I and diamond is With a specific gravity of 1. It will not completely dissolve in organic solvents.
Amber usually occurs as small irregular masses, nodules, or droplets. Although it can be many different colors, it is most often pale to golden yellow or orange and can be fluorescent. After a few years of exposure to light and air, amber often turns dark red and develops numerous cracks on the surface. Some amber is translucent or even transparent. However, trapped air bubbles can cause amber to be cloudy or opaque. Amber is a poor conductor of heat and large changes in temperature can cause it to fracture.
Amber is extracted in different ways, depending on its location. Baltic amber washes up along the shores of the Baltic Sea and as far away as Denmark, Norway, and England.
The largest deposits of North American amber are found on the surface of openpit clay mines in Arkansas. In New Jersey, Cretaceous amber is dug from the sand and clay of abandoned pit mines. It is screened, washed, and examined for inclusions. Sold amber can be imitations, the most common are young resins that are not fully formed into amber or stained glass or plastic. A way to know if yours is real is that it should float in saltwater.
Amber can be differently coloured and look in a number of different ways. A light honey colour is typical but amber can range from a white-ish colour to almost black and even blue or red.
It depends on the type of tree. Clearer amber is from resin excreted on the bark, cloudier amber comes from the inside of trees. Join the ZME newsletter for amazing science news, features, and exclusive scoops. More than 40, subscribers can't be wrong. Amber can be found all around the world. It can be open or underground mined. Amber has been taken from here since the 12 century. Sometimes amber is washed up from the sea floor and ends up on the beach or collected by diving or dredging.
One type of amber called Dominican is a blue colour, and highly prized because it is so rare. It is mined through bell pitting which is dangerous because the tunnels can collapse. Amber is a beautiful stone that takes millions of years to form.
Now you can appreciate this fact if you own any amber. I've always liked the way that words can sound together. Combined with my love for nature and biology background , I'm interested in diving deep into different topics- in the natural world even the most mundane is fascinating! Home Other Did you know? January 28,
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