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I know where my placenta is. Do you?
posted: August 19,
Shares 0After reading
, these words in her post just jumped off the page..
Under other circumstances, with a less complicated pregnancy, I would have gotten my wool-clad midwife to light some candles, sunk down in the birthing tub, and pushed those babies out like Ina May Gaskin herself. I would have worn braids. I would planted the placentas under magnolia and olive trees and done the whole circle of life thing. Ok, maybe not the placenta part.
Ahhh, the good ole placenta. The midwives stick it in a bowl with a loud sploosh, they examine all the blood vessels and such, then they neatly package it in a ziploc bag and shove it in your freezer. While you are oohing and aahing over your cute little babe with the squished face and jacked up head, they are doing away with your placenta and sewing you up like a patchwork quilt at the county fair.
You see, it is illegal to throw a placenta away. It’s considered bio-hazardous material. Yep, that freezer bag full of what appears to be marinated carne asada is like, totally dangerous.
It costs money to dispose of your placenta, people. So we did exactly what Samantha wrote in her post. We bought a tree (in our case, a Crepe Myrtle) and tossed it into the ground, the thing that efficiently housed my baby for 42 weeks.
Yep, 42 weeks. Isn’t that ridiculous? I even had a pregnancy that went as far as 43 weeks. Now that one was ridiculous.
Did it seem strange that we were all standing around the freshly opened up Earth when the placenta was lovingly tossed in? Perhaps. But it was definitely strange that I had my daughter’s placenta in the freezer for exactly two and a half years before we were led to finally bury it.
I guess it just got tossed in the back behind the bags of frozen spinach and peas. Maybe it was having all those kids back to back. But I promise, I put the placentas from my other homebirths I had in the Earth sooner, and not with a toddler holding my hand.
And yes, that is a picture of my actual placenta in my spare freezer.
Denise Cortes is a writer and artist who hails from Southern California. This Latina mom loves to share stories about...
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This article needs additional citations for . Please help
by . Unsourced material may be challenged and removed. (September 2016) ()
A crystal of
Microscopically, a
has atoms in a near- a
is composed of many microscopic crystals (called "" or "grains"); and an
solid (such as ) has no periodic arrangement even microscopically.
A crystal or crystalline solid is a
material whose constituents (such as , , or ) are arranged in a highly ordered microscopic structure, forming a
that extends in all directions. In addition, macroscopic
are usually identifiable by their geometrical shape, consisting of flat
with specific, characteristic orientations. The scientific study of crystals and crystal formation is known as . The process of crystal formation via mechanisms of
The word crystal derives from the
word κρ?σταλλο? (krustallos), meaning both "" and "", from κρ?ο? (kruos), "icy cold, frost".
Examples of large crystals include , , and . Most inorganic solids are not crystals but , i.e. many microscopic crystals fused together into a single solid. Examples of polycrystals include most , rocks, , and . A third category of solids is , where the atoms have no periodic structure whatsoever. Examples of amorphous solids include , , and many .
Crystals are often used in
practices such as , and, along with , are sometimes associated with
beliefs and related religious movements.
Halite (table salt, NaCl): Microscopic and macroscopic
Microscopic structure of a
crystal. (Purple is
ion, green is
ion.) There is
in the atoms' arrangement.
Macroscopic (~16cm) halite crystal. The right-angles between crystal faces are due to the cubic symmetry of the atoms' arrangement.
The scientific definition of a "crystal" is based on the microscopic arrangement of atoms inside it, called the . A crystal is a solid where the atoms form a periodic arrangement. ( are an exception, see .)
Not all solids are crystals. For example, when liquid water starts freezing, the phase change begins with small ice crystals that grow until they fuse, forming a
structure. In the final block of ice, each of the small crystals (called "" or "grains") is a true crystal with a periodic arrangement of atoms, but the whole polycrystal does not have a periodic arrangement of atoms, because the periodic pattern is broken at the . Most macroscopic
solids are polycrystalline, including almost all , , , , etc. Solids that are neither crystalline nor polycrystalline, such as , are called , also called , vitreous, or noncrystalline. These have no periodic order, even microscopically. There are distinct differences between crystalline solids and amorphous solids: most notably, the process of forming a glass does not release the , but forming a crystal does.
A crystal structure (an arrangement of atoms in a crystal) is characterized by its unit cell, a small imaginary box containing one or more atoms in a specific spatial arrangement. The unit cells are
in three-dimensional space to form the crystal.
is constrained by the requirement that the unit cells stack perfectly with no gaps. There are 219 possible crystal symmetries, called . These are grouped into 7 , such as
(where the crystals may form cubes or rectangular boxes, such as
shown at right) or
(where the crystals may form hexagons, such as ).
crystal is growing, new atoms can very easily attach to the parts of the surface with rough atomic-scale structure and many . Therefore, these parts of the crystal grow out very quickly (yellow arrows). Eventually, the whole surface consists of smooth,
faces, where new atoms cannot as easily attach themselves.
Crystals are commonly recognized by their shape, consisting of flat faces with sharp angles. These shape characteristics are not necessary for a crystal—a crystal is scientifically defined by its microscopic atomic arrangement, not its macroscopic shape—but the characteristic macroscopic shape is often present and easy to see.
crystals are those with obvious, well-formed flat faces.
crystals do not, usually because the crystal is one grain in a polycrystalline solid.
The flat faces (also called ) of a
crystal are oriented in a specific way relative to the underlying : they are
of relatively low . This occurs because some surface orientations are more stable than others (lower ). As a crystal grows, new atoms attach easily to the rougher and less stable parts of the surface, but less easily to the flat, stable surfaces. Therefore, the flat surfaces tend to grow larger and smoother, until the whole crystal surface consists of these plane surfaces. (See diagram on right.)
One of the oldest techniques in the science of
consists of measuring the three-dimensional orientations of the faces of a crystal, and using them to infer the underlying .
is its visible external shape. This is determined by the
(which restricts the possible facet orientations), the specific crystal chemistry and bonding (which may favor some facet types over others), and the conditions under which the crystal formed.
By volume and weight, the largest concentrations of crystals in the Earth are part of its solid . Crystals found in rocks typically range in size from a fraction of a millimetre to several centimetres across, although exceptionally large crystals are occasionally found. As of 1999, the world's largest known naturally occurring crystal is a crystal of
from Malakialina, , 18&#160;m (59&#160;ft) long and 3.5&#160;m (11&#160;ft) in diameter, and weighing 380,000&#160;kg (840,000&#160;lb).
Some crystals have formed by
processes, giving origin to large masses of crystalline . The vast majority of
are formed from molten magma and the degree of crystallization depends primarily on the conditions under which they solidified. Such rocks as , which have cooled very slowly and under great pressures, have com but many kinds of
were poured out at the surface and cooled very rapidly, and in this latter group a small amount of amorphous or
matter is common. Other crystalline rocks, the metamorphic rocks such as ,
and , are recrystallized. This means that they were at first fragmental rocks like ,
and have never been in a
condition nor entirely in solution, but the high temperature and pressure conditions of
have acted on them by erasing their original structures and inducing recrystallization in the solid state.
Other rock crystals have formed out of precipitation from fluids, commonly water, to form
veins. The
and some limestones have been deposited from aqueous solution, mostly owing to
in arid climates.
Water-based
in the form of ,
is a very common manifestation of crystalline or polycrystalline matter on Earth.[] A single
is a single crystal or a collection of crystals, while an
Many living
are able to produce crystals, for example
in the case of most
in the case of .
The same group of atoms can often solidify in many different ways.
is the ability of a solid to exist in more than one crystal form. For example, water
is ordinarily found in the hexagonal form , but can also exist as the cubic , the
, and many other forms. The different polymorphs are usually called different .
In addition, the same atoms may be able to form noncrystalline . For example, water can also form , while SiO2 can form both
(an amorphous glass) and
(a crystal). Likewise, if a substance can form crystals, it can also form polycrystals.
For pure chemical elements, polymorphism is known as . For example,
are two crystalline forms of , while
is a noncrystalline form. Polymorphs, despite having the same atoms, may have wildly different properties. For example, diamond is among the hardest substances known, while graphite is so soft that it is used as a lubricant.
is a similar phenomenon where the same atoms can exist in more than one
in a beet sugar factory.
Crystallization is the process of forming a crystalline structure from a fluid or from materials dissolved in a fluid. (More rarely, crystals may b see
Crystallization is a complex and extensively-studied field, because depending on the conditions, a single fluid can solidify into many different possible forms. It can form a , perhaps with various possible , , impurities, , and . Or, it can form a , with various possibilities for the size, arrangement, orientation, and phase of its grains. The final form of the solid is determined by the conditions under which the fluid is being solidified, such as the chemistry of the fluid, the , the , and the speed with which all these parameters are changing.
Specific industrial techniques to produce large single crystals (called ) include the
and the . Other less exotic methods of crystallization may be used, depending on the physical properties of the substance, including , , or simply .
Large single crystals can be created by geological processes. For example,
crystals in excess of 10
are found in the
in Naica, Mexico. For more details on geological crystal formation, see .
Crystals can also be formed by biological processes, see . Conversely, some organisms have special techniques to prevent crystallization from occurring, such as .
Two types of crystallographic defects. Top right: . Bottom right: .
An ideal crystal has every atom in a perfect, exactly repeating pattern. However, in reality, most crystalline materials have a variety of , places where the crystal's pattern is interrupted. The types and structures of these defects may have a profound effect on the properties of the materials.
A few examples of crystallographic defects include
(an empty space where an atom should fit),
(an extra atom squeezed in where it does not fit), and
(see figure at right). Dislocations are especially important in , because they help determine the .
Another common type of crystallographic defect is an , meaning that the "wrong" type of atom is present in a crystal. For example, a perfect crystal of
would only contain
atoms, but a real crystal might perhaps contain a few
atoms as well. These boron impurities change the
to slightly blue. Likewise, the only difference between
is the type of impurities present in a
crystal group.
In , a special type of impurity, called a , drastically changes the crystal's electrical properties. , such as , are made possible largely by putting different semiconductor dopants into different places, in specific patterns.
is a phenomenon somewhere between a crystallographic defect and a . Like a grain boundary, a twin boundary has different crystal orientations on its two sides. But unlike a grain boundary, the orientations are not random, but related in a specific, mirror-image way.
is a spread of crystal plane orientations. A
is supposed to consist of smaller crystalline units that are somewhat misaligned with respect to each other.
In general, solids can be held together by various types of , such as , , , , and others. None of these are necessarily crystalline or non-crystalline. However, there are some general trends as follows.
are almost always polycrystalline, though there are exceptions like
and single-crystal metals. The latter are grown synthetically. (A microscopically-small piece of metal may naturally form into a single crystal, but larger pieces generally do not.)
materials are usually crystalline or polycrystalline. In practice, large
crystals can be created by solidification of a
fluid, or by crystallization out of a solution.
solids (sometimes called ) are also very common, notable examples being
and . Weak
also help hold together certain crystals, such as crystalline , as well as the interlayer bonding in .
materials generally will form crystalline regions, but the lengths of the molecules usually prevent complete crystallization—and sometimes polymers are completely amorphous.
The material
(Ho–Mg–Zn) forms , which can take on the macroscopic shape of a . (Only a quasicrystal, not a normal crystal, can take this shape.) The edges are 2&#160;mm long.
consists of arrays of atoms that are ordered but not strictly periodic. They have many attributes in common with ordinary crystals, such as displaying a discrete pattern in , and the ability to form shapes with smooth, flat faces.
Quasicrystals are most famous for their ability to show five-fold symmetry, which is impossible for an ordinary periodic crystal (see ).
has redefined the term "crystal" to include both ordinary periodic crystals and quasicrystals ("any solid having an essentially discrete
diagram").
Quasicrystals, first discovered in 1982, are quite rare in practice. Only about 100 solids are known to form quasicrystals, compared to about 400,000 periodic crystals known in 2004. The 2011
was awarded to
for the discovery of quasicrystals.
Crystals can have certain special electrical, optical, and mechanical properties that
normally cannot. These properties are related to the
of the crystal, i.e. the lack of rotational symmetry in its atomic arrangement. One such property is the , where a voltage across the crystal can shrink or stretch it. Another is , where a double image appears when looking through a crystal. Moreover, various properties of a crystal, including , , and , may be different in different directions in a crystal. For example,
crystals consist of a stack of sheets, and although each individual sheet is mechanically very strong, the sheets are rather loosely bound to each other. Therefore, the mechanical strength of the material is quite different depending on the direction of stress.
Not all crystals have all of these properties. Conversely, these properties are not quite exclusive to crystals. They can appear in
that have been made
or —for example, .
is the science of measuring the
(in other words, the atomic arrangement) of a crystal. One widely used crystallography technique is . Large numbers of known crystal structures are stored in .
crystals .
: A type of ice crystal (picture taken from a distance of about 5&#160;cm).
, a metal that easily forms large crystals.
An apatite crystal sits front and center on cherry-red rhodochroite rhombs, purple fluorite cubes, quartz and a dusting of brass-yellow pyrite cubes.
of , like this one, are an important type of industrially-produced .
A specimen consisting of a bornite-coated chalcopyrite crystal nestled in a bed of clear quartz crystals and lustrous pyrite crystals. The bornite-coated crystal is up to 1.5&#160;cm across.
Stephen Lower. .
Ashcroft and Mermin (1976). Solid state physics.
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Howard, J. M Darcy Howard (Illustrator) (1998). . Bob's Rock Shop.
Krassmann, Thomas (). . Krassmann.
Various authors (2007). . Commission on Crystallographic Teaching.
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Various authors (2010). . , Department of Crystallography.
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