Is it possible to have two different structure in a single crystal?
539041
Yes it is possible. BUT are you sure its a single crystal. Was the growth or cooling rate the same? Are there other impurities, compounds, molecules etc in the crystal to cause it to change its structure?
700100
Many other materials can be in three states. It depends on the temperature!\nNear the 'triple point' the three phases exist together.\n\nTh
846910
No. They do not share the same dimensions.\n\nYou can multiply them though.
435301
All crystals do possess symmetry. Based on thier symmetry, it is possible to simplify thier physical characteristics. Changes from one particular configuration to another "indistinguishable" configuration can be performed by a set of symmetry operators or rules. These mathematical rules or sets of operators is what is known as group theory.\nHence, if one knows what group a particular symmetry is defined by then, under the construct and rules of theat group the properties or behavior of a crystal when subjected to an external 'field' which can be parametrized as an operator can be generally determined apriori before its tested experimentally.
450305
The question was presented as an example of something puzzling - you have a substance - tartaric acid if i remember that is not optically active and then you have the same substance (but made as a result of microbial activity) that has identical properties, the only difference is that it is optically active - nobody then knew why\n\nhe let the optically inactive solution  crystalize, looked really close and well and compared - then noticed that the crystals differ - are like a miror image, he manually sorted them out and WOW the 2 solutions were optically active - the same degree but oposite direction (if you understand me, i do not know what this is called in english). then he assume that the microbes can do the sorting in their body. He spent his lifetime looking in microscopes or experimenting with unbelievable patience while enyybody else would have given up long time ago, thats why he made so many breakthroughs
937834
Well, you are getting in to a bit more complicated chemistry. For the question you are asking, the simple answer is No. However there are multi-valence ions, such as Oxygen. Normally Oxygen would gain 2 electrons making it O(2-) but it has another valence of 1 where it only gains one electron and becomes O(1-). By the sounds of it you are not at this point so don't worry about but you will get there eventually. In order to understand multi-valence you need a Periodic Table of Elements that lists all the valences of each element. This makes bonding harder, etc,etc so I wouldn't worry about it if I were you, yet.\n\nSo to simply answer your question, No, it is impossible for Magnesium
677372
here are some useful sites visit them-\n\nhttp://www.stolaf.edu/people/hansonr/mo/x-ray.html\n\nhttp://news.uns.purdue.edu/html4ever/9804.Crystallography.html
778725
Consider one cube of the lattice.  there will be one atom on each corner.\n\nWith BCC there will be one atom in the centre of the cube.\nWith FCC there is one atom in the centre of each face of the cube - a dice with one spot on each face.\nIt's a very long time since I did this, but I think steel is BCC at normal temperatures and chnges to FCC on heating.
848041
There are nearly an infinite number of possible shapes, all based on a six sided crystal.\n\nIt is NOT necessarily true that no two are alike.  No one can say for certain since there is no way to study a nearly infinite number of snowflakes to make a comparison.\n\nBut consider this possibility, that there are two snowflakes with the EXACT same pattern and layout.  One is an inch in diameter, and the other is 3/4 inch.  We can say that thes are not alike since they are of different sizes.  We can assume that it is possible that the exact same pattern may appear in another flake that is one inch in diameter, and another that is 1/4 inch, and any size in between those I've mentioned.  \n\nWhat if two appeared that were the same size within a thousandth of an inch?  We can't say that the are exactly the same.  But what if two appeared, but the difference in size were too small to measure?  ARE they the same?\n\nEven if there were a LOT of money to spend on such a research project, the research could only go so far.  If the study were done in Colorado, for instance, there would be no way to know if a duplicate appeared outside of Moscow, or New York, or Lake Tahoe, or even right outside the researcher's door.\n\nJust because there are NEARLY infinite possibilies of patterns, the fact that nature limits the patterns to six sides means that there is a potential limit to the number of patterns.  And don't forget, nature is not TRYING to prevent duplication.  The same kinds of physical forces are in place in the making of EVERY single snowflake, all over the world.\n\nThere are nearly an infinite number of ways a human being can appear, but, for the most part, we all fall into the usual pattern of one head, two arms and two legs.  In between, there is a great variety in skin color, size, shape of head, hand, belly and bottom.\n\nSame for snowflakes
167709
No it can come out very different, depending on the materials involved.\n\nThe light can come out a different color. \nThe light can come out a different amplitude. \nThe light can come out in a different direction. \nThe light can come out with a different polarization.\nThe light can come with a phase lag.
1159126
Actually your mineral dealer is right.  In any crystalline structure there are vibrations that physicists refer to as phonons.  It is a quantum effect.  If you are generally interested, look into solid state physics.  But this is not unique to mineral crystals, metals which also have a crystalline structure do the same thing, in fact anything with a crystalline structure.  \n\nThese phonons are responsible for transferring of thermal energy and are also responsible for metals expanding  when heated.  You can even have groups of atoms vibrate together at acoustic frequencies and these are called acoustic phonons.  Phonons exhibit the same wave/particle duality of other quantum effects, like photons.\n\nCan these phonons communicate with you body.  I doubt it.  Phonons are generally reflected when they hit the surface of a crystal.  Even if they did manage to make their way to your body, you would need something to match the frequency or the energy would be lost as heat.  There are also phonons on the surface called...you guessed it, surface phonons.  \n\nNo matter what type of phonon, you would need something that could vibrate at that specific frequency or the energy would be dispersed as heat.  In addition I find it hard to believe that the energy from these phonons is large enough to really do anything physiologically.
63207
You can make a crystal by combining diff. elements...\n\ne.g:\ncombining carbon, hydrogen and oxygen will result to glucose molecules which will made up to SUGAR CRYSTALS.\n\nI think these are some of the diff. kinds of crystals...\n\nIceland SPar\nAlbite, orthoclase, pyrite, apophylite, anhydrite, quartz...
783612
No idea what your saying, but NaCl does form crystal lattices which are like perfect cubes because every Na is bonded front and back, side to side, and other side to other side with a Cl therefore forming a cube like structure. Check out the picture in the website listed below, Cl is green Na is gray.
691753
maybe a hexagonal prism http://en.wikipedia.org/wiki/Hexagonal_prism http://en.wikipedia.org/wiki/Prism_%28geometry%29
859386
Due to differences in chemical structures
38380
hum...not sure you can do that, however, if you want to have to beams (more or less the same as two different lasers, depending on the purpose of your experiment) in phase with each other, you can use something to split the beam (a beam splitter), and, with a coupla mirrors organized in a certain configuration, you should be able to have 2 lasers in phase
1117871
Yes.\nSince a typical small snow crystal might contain 1018 water molecules, we see that about 1015 of these molecules will be different from the rest.  These unusual molecules will be randomly scattered throughout the snow crystal, giving it a unique design.  The probability that two snow crystals would have exactly the same layout of these molecules is very, very, very small.  Even with 1024 crystals per year, the odds of it happening within the lifetime of the Universe is indistinguishable from zero.