what is the crystal shape?
455972
There are many crystal shapes.  The standard is an elongated six sided coming to a pyramid like point at the top.  Some, however, are double terminated (have points at both ends). Some (such as garnets) have six sides, but are flat on top and almost roundish looking.  Others, such a mica, are in flat layers.  Others still, can come in cubes (such as pyrite)  Some crystals have no particular shape at all (globular)(such as malachite).  So there is no one particular crystal shape.
1143581
Just answered this question for someone else:\n\nhttp://www.bestcrystals.com/ulexite.htm\n\nhttp://www.northwestnatureshop.com/department/Rocks_and_Minerals/Rock_and_Mineral_Specimens/592.html
161967
It is a basic molecular building block of silicate minerals. It consists of 4 oxygen atoms arranged in a tetrahedron shape around a silicon atom. \nHere's a diagram to see the shape:\nhttp://www.geo.wvu.edu/~wilson/geol1/lec15/lec153.htm\n\nThe bonds in a silicate tetrahedron: oxygen is -2, silicon is +4 and the net charge is -4\n\nThere are six ways to bond molecules of silicate tetrahedrons:\n1. Individual tretrahedrons connected by cations\n2. Chain structure joined by cations\n3. Double chains joined by cations\n4. Sheet structure  joined by cations\n5. Framework structure joined by covalent bonds\n6. Ring structure\n\nOne combination of the above is worth noting, being feldspar which has aluminum ions substituting for some of the silicon and there are ionic bonds with the aluminate tetrahedrons and some covalent bonds between the silicate tetrahedrons. \n\nThe silicates form an incredibly large group of minerals. You can go here to see most of them: http://www.webmineral.com/strunz/VIII.shtml\n\n\nThis question is leading up to the classes or groups of minerals. There are a number of classes built around having common molecular building blocks. \n\nTwo of the classification systems are Dana Classification and Strunz Classification. You can see these here:\nhttp://www.webmineral.com/strunz.shtml\nhttp://www.webmineral.com/danaclass.shtml\n\n\nPlease go back and look at my answer for one of your questions on quartz/calcite. I added an answer to the question you asked on your first post, which I just noticed. How are we doing? Is this helping?
268958
I would say yes, this is how the crystals form.
481051
cleavage is the splitting of a crystal along planes of atoms in the lattice \n\nthe faces are just the outer surfaces eg the faces of a diamond all have the same angles \n\nhope this helps!
47208
A snowflake's shape reflects the internal order of the water molecules. Water molecules in the solid state, such as in ice and snow, form weak bonds (called hydrogen bonds) with one another. These ordered arrangements result in the symmetrical, hexagonal shape of the snowflake. During crystallization, the water molecules align themselves to maximize attractive forces and minimize repulsive forces. Consequently, water molecules arrange themselves in predetermined spaces and in a specific arrangement. Water molecules simply arrange themselves to fit the spaces and maintain symmetry.
1155007
Crystal growth can occur at about any speed, but if you want a regular single crystal, the slower it grows the less likely are defects. Sudden growth leads to snowflake-like dendrition. Certain minerals like e.g. diamond require some time and extreme conditions to crystallize.\n\nWindows for IR purposes can be either defined minerals or glasses. While glasses are formed by undercooling melts, for some mixtures that might take longer.
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?
787518
What the first reply means is that since it is ionic, it does not have a molecular shape.  It is NOT a molecule.  The Zn+2 ion and the Br- ions will form crystals.  They have a unit formula of ZnBr2 (not znbr2) but it is not a molecule.
448881
I've never heard of that specific term.  But the verb "crystallize" has four different meanings:\n\n\n1: cause to take on a definite and clear shape\n \n2: make free from confusion or ambiguity; make clear\n\n3: cause to form crystals or assume crystalline form\n\n4: assume crystalline form; become crystallized
948227
a crystal structure is a unique arrangement of atoms in a crystal. A crystal structure is composed of a unit cell, a set of atoms arranged in a particular way; which is periodically repeated in three dimensions on a lattice. The spacing between unit cells in various directions is called its lattice parameters. The symmetry properties of the crystal are embodied in its space group. A crystal's structure and symmetry play a role in determining many of its properties, such as cleavage, electronic band structure, and optical properties.\n\n\nThe crystal structure of a material is often discussed in terms of its unit cell. The unit cell is a spatial arrangement of atoms which is tiled in three-dimensional space to describe the crystal. The unit cell is given by its lattice parameters, the length of the cell edges and the angles between them, while the positions of the atoms inside the unit cell are described by the set of atomic positions (xi,yi,zi) measured from a lattice point.\n\nFor each crystal structure there is a conventional unit cell, which is the smallest unit that has the full symmetry of the crystal (see below). However, the conventional unit cell is not always the smallest possible choice. A primitive unit cell of a particular crystal structure is the smallest possible unit cell one can construct such that, when tiled, it completely fills space. This primitive unit cell does not, however, display all the symmetries inherent in the crystal. A Wigner-Seitz cell is a particular kind of primitive cell which has the same symmetry as the lattice.\n\n\nfor further clarifications go to the site listed
175854
http://en.wikipedia.org/wiki/Seed_crystal
881405
1. A diamond is a specific type of crystal form of Carbon (contrary to what some people say and what some have answered:  a diamond was NEVER coal -- the only similarity is that they both contain carbon.)\n2. You cannot "make" a diamond out of a crystal.\n3. You can try to cut a crystal to maybe resemble a cut diamond, but no one would ever confuse the two.\n4. Crystals have certain alignments of the crystal facies along which the crystal will split -- it is along these facies that an expert will "cut" a crystal to get a specific shape.
55435
jtkeel is mostly right, except the structure of copper is not crystaline.  Al3K is right about the structure of copper, which is the basic structure of all metals and is what gives them their physical characteristics, like their malleability, conductivity and so forth.
583380
A crystal is non-living, does it make any sense for it to grow, as they do, 'knowing' what color to be, what shape and size and how many facets and what angles to have and what clarity and hardness to have and what refractive index to have and give off little baby crystals which will grow up in the likeness of the parent. You could liken our DNA to a kind of protein crystal, It 'knows' what to do because the data is contained within its molecular structure. There is no reason for it so it makes no sense but none the less, it occurs naturally. We have to accept that we were created by our genes as a mere vehicle for its own use.
476288
for a crystal to form it needs to grow off of some thing. In this case usually a speck of dust. \nAfter that the crystal has a geometric shape. The dendrite grows in one direction. Then another cyrstal neucleates off the side of the first and another dendrite grows.\nThis occurs in all crystals.\nIt is how they make steel hard, by making the dendrites smaller by cooling it faster
168138
no it isn't. Iodine is the central atom and has 3 bonding pair and 2 nonbonding pair, a total of 5 pairs of electrons.\nthat would make it trigonal bipyramidal, more specifically we call it T shaped.