Crafting Glass

yes, the bottles are "melted" but it is done in a glass kiln, at a temp of 1200 to 1400 degrees and kept at that temp for anywhere from 1 to 3 hours and then "cooled" from 3-6 hours.
Kiln work can be tricky at first, it would be best to first know how to operate a kiln and know what type of glass to be using. A great website to check out on fused glass(melted glass) is warmglass.com. Good luck.

I found this weird rock that looks like kryptonite or something,and it cuts glass.

Window glass has a hardness of 5.5 on the Moh's hardness scale, and so could be scratched by feldspar, quartz, topaz, corrundum and diamond. Nearly all precious and semi-precious gems are harder than glass, so scratching glass is no test for a diamomd.
Here's a reference to Moh's scale:

http://en.wikipedia.org/wiki/Mohs_scale

…I need to cut a cigar tube's closed end to make it an open end (i.e. just a glass tube)….will a dremel do this safely or will I just break the glass? How could I go about cutting the end off a closed tube?

Yes. Here's how. To make the cut, you require the diamond tipped tool that comes with the tool (such as a Dremel or any similar high speed multipurpose tool) or purchase one. They look like a small ball stuck on the end of the shaft. I cut from both sides and had someone spraying water using an atomizer bottle on it the entire time. This cooled the bit and glass, also providing some lubrication and avoiding the generation of glass dust. A dam around the hole to hold in the water over the cut doesn't work very well, since the glass/water slurry will obscure your vision of the cut.
Do not force the bit to cut the glass, this does not speed up the process. Just let the bit do the work and gently pass around the hole taking a small amount of glass out at a time.
If you have access to a Dremel or similar tool don't be afraid to have a go at drilling your own holes.

I'm installing a backsplash comprised 1" x 1" glass tiles. They are 8mm thick and have a colored backing to them. I'm concerned about how to go about making sure I get a clean cut without screwing up the colored backing. Can I still score and snap these tiles or do I need a wet saw?

Don't waste your time, do it right, get a wet saw from a rental place.

he is creating a weak point where the glass will break

My daughter broke the glass on the wood heater and I want to cut the glass from and old electric oven door to replace it. I have a grinder and was hoping there might be a glass cutting wheel I could use to cut the oval shape.

I used to be a glazier. Dont bother with trying to cut the glass from the old electric oven door. If it is tempered you will not even be able to cut it without it shattering into a million pieces. You need to use tracing paper, newspaper, etc. to make a pattern of the exact size of the oval shape you need to cut, then you can take it to a glass company and they will do it for under fifteen bucks, or you can purchase a piece of glass (make sure you get the correct thickness) for under $5. If you are going to try to cut the oval (and I dont recommend it), you have to use a Sharpie to transfer the pattern to the glass. Then you cut as follows, from the left edge of the glass around the upper half of the oval all the way to the right edge of the glass. Snap this off, then cut around the bottom edge of the oval. You will not get a clean break on any of this, and will have to nip around it with glass pliers. Really, you will waste more time and money trying to do this yourself. Go to the Glass company, it's cheap.

i m doing a project with glass bottles.. for tat i need to connect two bottles directly.. i prefered to cut a hole in bottom side of d bottle using diamond cutter bit.. but it's too costly i can't afford for many bottles.. plz give me a better solution..

What about those tungsten carbide drill bits? They are cheap (particularly in smaller sizes) and will work well if you press steady and use some water for a lube as you drill.

its an add water mix and gets mouldy after a week or so,it also has a soapy(liquid) feel to it leading me to thing it may be glyceren.i buy this stuff and add water to it to cut glass beads on a diamond saw to keep it running cool,and to add life to the diamond wet saw blade.how can i make it myself?

I use Crystal Cut with my diamond saws. It is a water additive that is a rust inhibitor and should be used with diamond wheels and trip saws

You only need to mix 1 ounce of this to a gallon of water–a lot of bang for the buck. I buy 5 pounds of it for about $23.00, or 80 gallons worth at about 29-cents a gallon.

To skimp on this type of product in your lapidary workshop is to be penny-wise and pound-foolish. If you use water alone your equipment will rust out quickly and will be expensive to replace.

I've never found it to get "mouldy" or cloudy and I've had jugs of it sitting around for several weeks. If you are using a different brand, you may want to consider switching. Any reputable lapidary supply such as Kingsley North should be able to provide it for you.

Any cutting surface will dull knives over time. Glass does it quicker and the sound is very irritating when cutting.

I need a new glass cutting board, but I don't like any of the designs available & I really don't want a clear one. Is it possible to put your own design onto one of these? What is the process that the manufacturers use? I know there are companies that will personalize them for you, but I'm a "do-it-yourselfer" & I'd really like to try it for myself…

I agree that there is little hope of you actually "tempering" the glass on your own, and in fact, it would probably be dangerous for you to try. This leads me to my next point: a tempered glass cutting board is not a good idea.

Tempering a glass involves heating the outside edges of a piece of glass, which causes the outside to cool differently than the inside when the glass was formed. This puts a compressive stress on the surface of the glass. Glass will only break under tension (crack formation and growth) so a compressive stress on the surface acts to close any cracks that form, making the glass stronger. The problem is it's very difficult to evenly heat and cool the outside edge so you get an uneven compressive stress on the surface. Even professional manufacturers have difficulty making a stable tempered glass without regions of stress concentration. These tempered defects cause focus points of stress and can lead to explosive failure even under just its own internal forces. The other issue with tempered glass, and the reason why it's not used as bullet-proof glass (and cutting boards), is it cannot absorb multiple impacts. Once it does crack it breaks into thousands of small blunt pieces in a process known as dicing. A true strong glass is usually just a very thick piece of glass that can absorb multiple impacts and heavy cracking before failing completely.

They do make glass-ceramic cutting boards, made from the same material as the flat top stoves. These are carefully crystallized glasses, which are very strong and very stable. You still couldn't make a glass-ceramic without some serious equipment, but if you're looking for something different try out one of them.