Yesterday my boyfriend and I went to Harbor Freight to pick up a cheap tool or two. I suddenly thought about looking for some sort of affordable saw blade up to cutting rock, tile, brick, etc. I found a pair of 2 hacksaw blades that supposedly cut such things. I am not sure if they are diamond or not. I figured for $5, if they didn't work, it wouldn't be a huge loss.
My father dug up an antique hack saw that wasn't being used, and I installed the blade. I chose one rock to experiment on, and went outside onto the porch. All I did was hold the rock against a chair and started to saw. Good thing it is windy today, because there was stone dust everywhere! Attached are photos of my progress in a couple of minutes.
I will have to try actually holding the rock in a vise (without damaging the minerals I want to save) and actually saw correctly.
I am wondering if I should be using water as I saw? Does it matter with a low-speed approach such as mine?
Being a beginner, this is probably only a big deal to me... but I wanted to share my experience anyway. I will let you all know if I get all the way through the rock later!
Now that the rock in your photo has a nice deep grove into it, I would now brace it in a substantial vise. No further sawing might be needed. Then with a wide chisel in the groove, give the chisel a sharp tap with a crack hammer or hand sledge and it should spit the rock right where the groove has been made. This works for me quite well, but examine the rock first to make sure no hairline cracks are in other areas of the rock or the break might occur into these hairline cracks and not exactly where you want them. Hope this helps. CHEERS.....BOB HI Bob
This particular sample seems to have no "fault lines", which is why it was giving my chisel such trouble in the first place. I am not totally sure what the stone is, I think dolomite marble (from the Chelmsford MA lime quarry). I may try your chisel idea, but I really want to see if I can saw through the whole thing. I've been wondering for so long if I can do it!
:-) Wellp... it took a LONG time and a lot of muscle, but I finally got the rock cut in two. Hardly seems worth the effort. And despite my best efforts, the mineral side still got a little damaged. Looks like this technique may only work:
A) with softer material
B) with a better vice
C) for someone with a better vice in a room with air conditioning and not a basement!
D) for someone with more patience
E) for someone with more stamina
A mechanical technique would be far FAR better... But I may try again and see what happens.
Yard sales and thrift shops often have tile saws that work well for small specimens and trimming. You can usually find them for $25 or less. Use the blade that came with it and start saving for a new one when that wears out. Surprisingly the tile blades last a really long time unless you are cutting quartz-based (jasper, agate, etc.) or jade-based (nephrite or jadeite) specimens. When it comes time to get a new blade buy a blade specifically for granite. It will make short work of everything including quartz-based and jade-based rocks as long as you don't push too hard and try to cut really fast and it will last a long time.
I found out early on that nothing was really comparable and I spent twice what I paid for my first tile saw experimenting with this and that. I still have the same saw I bought years ago and am only on my 2nd granite blade and I have made many hundreds of cuts on agate, jasper, and nephrite jade.
My 2-cents
Doug Thanks for the info, Doug. Seems a lot of folks go with tile saws. I have yet to find one and see what they look like. Can they cut rocks/minerals that are rather large? Say, 4-5" around? Or are they better for smaller items, like those used for jewelry? I can cut a 5" rock but it needs to be done from both sides. there's a knack to it and you learn quickly. I must say this: Please buy and use protective equipment: Safety glasses or shield, heavy gloves, long sleeved shirt, and heavy boots/shoes (for those rocks that inevitably get dropped on toes). I also wear a respirator at all times (you wouldn't think you would need one with all the water flying around but at the end of a cutting session blowing your nose will show you what you breathed in with the water mist).
If I have lapidary material that is large I put it aside and when I have enough I rent a large brick saw and cut it all then take the brick saw back. These days I don't do any lapidary work and use the tile saw strickly to trim for mineral specimens. The second link is what I rent to cut bigger stuff. I think that is a typo on craigslist. the blades on tile saws are 7" and they all cut at least a 2" with the guard on and a 3" with the guard off (NOT RECOMMENDED!!!!!) unless they have some kind of hand held mini-saw they are selling. this is what you want:
http://www.harborfreight.com/7-inch-portable-wet-cutting-tile-saw-40315.html
don't worry about the tilt table it is useless in my mind. I got this at a tag sale for $10 and it is the one I am still using. In your first post you said that being a beginner, it might not be new . . . but I appreciate it. I have had a wire for cutting brick, etc. that fits into a hacksaw frame, for years (got cheap at some yardsale once) but never got around to trying it. So I appreciate that someone did try it (might not be the same brand name but looks just like it) and found out how it works. Thanks for sharing this interesting information.
I had a little post a little while ago in this section on 12/20/2015 (a few pages back) "Cutting Excess Matrix with Angle Grinder" and that was a happy experience (even happier when I rigged up some safety stuff, like a clamp made of 2x4 wood and threaded rods, & nuts, to hold the specimen). So it is nice when others contribute also. 
Like Dana said, the angle grinder works really well with a diamond blade. If you have an angle grinder hanging around, the blades are pretty inexpensive. They work great for the smaller stuff and I have even used them in the field. I did take the guard off my grinder for added depth when cutting. I like to keep the blade wet or I burn through the diamonds to quick. I have kept a bucket of water near by and periodically dip the blade in while it is still spinning , or if you have two people, use a squirt bottle.
Using the hack saw it way too hard and time consuming, I know from experience trying to cut a quartz geode... I use a 10", wet tile saw. It can cut about 3.5" with guard and up to 8" with the guard off (at your own risk)... if you do two passes (top and bottom). Then, you can polish with hand sander and hand polisher (made for waxing a car) (if doing lapidary work). This is a relatively inexpensive mechanical set up. I would not recommend doing this until you are pretty deep into rock hounding and you have a decent amount of stuff to trim. I really only use it to cut out crystals that are in a matrix that will not yield them using hand chisels and hammer (my preferred method). So, instead of ruining the piece, I cut the matrix down... last resort though since many people don't like specimens that are cut. However, I would rather have a specimen than not... got some good ones that I would not have without a saw.
The saw blade (bought from Lowe's) is pretty good and has lasted a long time even cutting quartz. Only bad thing is that the yellow paint like to wear off onto the piece if you are not careful and try to cut too much off. Its not meant for deep cuts, so that is understandable.
Harbor Freight is where I got all my equipment... be on the lookout for deals as they usually offer coupons and discounts. Shipping can even be reduced with discounts. My set up was under $300 to include saw, blade, grinder, buffer, and misc sand paper and buffing grit. It is worth it considering the pieces I now have that I would not have had with out that equipment. Never thought of that... DO people dislike cut specimens? I mean, if there isn't a "fault line" in the right place allowing the rock to be broken where you want it, what else can you do?
Also, another drawback to the hacksaw wire... it is about 1/8" thick. So you need to factor this in when planning a cut. JONELLE, In general saw cuts on collector mineral specimens are frowned on. For lower end examples, to me, it really isn't a big deal when done well and the final trimmed specimen looks good. But on higher end examples and certainly most very hi end examples it seems to be a big deal. When there is a lot of extra matrix or unwanted portions of the specimen, many of these examples are first trimmed by saw cuts, but then the preparers obliterate the saw marks with further careful non-saw trimming so the final prepared specimen looks more natural. There are several types of non-saw trimmers that might be used and hi end specimen preparers use these pretty much on a regular basis. Hope this helps. CHEERS......BOB WOW... thanks, Bob! I didn't know that! But it does make some sense. If someone spends $500 on a specimen, a flat saw cut would look... well... like a big ol' saw cut. There are a few materials that trim better with saws than some other ways - if they have fractures (seen or unseen) that go right through the most interesting part of the specimen. Best to get advice on the particular material from someone who has worked with that material. Personally, I don't mind saw cuts as long as I either can't see them or they are unobtrusive - such as on bottom of specimen, or back, providing a nice flat surface on which to paste a good label. I think a similar principle applies to saw cuts (when unavoidable) as to use of mineral-tack, glues, fixatives (to mount a specimen onto a base): The fixative should, like underclothes (if you will pardon the expression) should work well but not be seen, or at least be not obvious. Also, be real careful, and think, and perhaps get some advice,, as one would be in any form of trimming, before you attempt it, particularly on any excellent specimen (doesn't matter so much on real common stuff - one gets experience that way!). Remember you can always trim it later if you want, but you can't get it back to what it was before.
