hi,where can i buy a hardness testing tool for test 4?ive seen some online that say they are for diamond testing,is that ok to use for other gems?
kassoy.com/prodcat/Hardness-Sets.asp about 90$ . look up the Mohs scale on the web you can make a set of your own .I use my finger nails, a copper coin, common nail , and a good file, Gem tools pro software will some times come up with rare a mineral that is close to your sample and hardness is a way to tell if you have one of these rare stones. Hint any thing under 5 on the mohs scale is not going to last well in most settings .
I agree with chrisa, you can look up the Wikipedia article on hardness and looking at the table, just make your own set. Fingernail, copper penny, piece of iron, piece of steel, piece of glass, piece of quartz, possibly a piece of clear topaz, a piece of synthetic corundum and a piece of CZ rough. If you have access to other gem roughs, such as garnet or tourmaline, these might fill in the intermediate steps. You could even get a diamond nailfile for #10!
With the steel, you’ll have to determine if it is garden variety or something very hardened, which would be higher on the scale. Same is true of the glass, as there are very soft glasses and some that are harder. By scratching the various samples with each other, you will establish a hierarchy and an approximate hardness for each. Some, like quartz, are going to be a definite value to test the others against. This is a great way to learn. Remember that these hardnesses are only approximate and are for separations where the hardness of two alternatives is a good bit different.
You might want to make friends with some people in the local gem club. The faceters will have pieces of various synthetic gems to give you or sell to you cheaply. Synthetic corundum is about ten cents a carat and synthetic quartz is similar in cost, ditto CZ.
hi chrisa,so how do u use the penny etc.So u scratch the same gem with each tool in turn,but how do u work out the hardness
Hardness For me is coarse filter some thing i use to separate soft ( say under 5) and hard ones 6,5 and up.The Mohs hardness scale is not liner the steps from say 8,9.10 are way bigger than say 3,4,5., I have never owned a hardness set just used what i had at hand this is not a point of pride i just did not want to carry one around , Start soft and work up and dont do any of this on someone else’s gem or rough without asking . I have pushed too hard hit cleavage plains and ya I over did it so go easy , On gems i look first if it is already scratched i note it and this is the first clue. If it is scratched it most likely is 8 or less. People are some times rough on gemstones but i have never seen a diamond with a polished facet with a scratch down it (yet). Chipped yes poor polish yes scratch no. Ok what dose all this come to , 10 you will not see scratches 1 will be dust in your hand, Now let us move to the center 5 this is not really the center as the scale is not liner but it is close to the cut off for standard mounting of gems, So you have a ring prong mounted gem no scratches if its not new or well taken care of it is hard most likely 7 or more way would you want to scratch it ? Ok you want to know if a piece of rough is 6.5 not just 6 or 7 to do this right you should use a hardness set with the right size tips on a clean surface dust and dirt on the surface can be harder than both the stone and the tester, If you make a set like the one Roy posted and get one from kassoy you would have the best of both, Dont push too hard as most of the sets we had at school were messed up and dull due to too much force being used. Start soft move up till you get an easy scratch then move back a half steep and try again use a lope to see the scratch.