japanese paper money,,is it worth??

[wacky22]

i need your suggestion what to do with this japanese paper money...and what is that yellow object i found..i dont know how to test an au..

[ghost]

Japanese money, no more value. But the 'yellow thing' has value..... it's a gold nugget if I'm not mistaken. Chip some and go to a pawnshop for testing... simple as that (if you have alibi where you got  those chip gold). My 2 cent worth.

[zeeker]

for me, it does look like bronze or copper. notice the bluish molds on it?
but i'm maybe wrong

[wacky22]

even me dont know what this things all about..

[Yojuyo]

for me, it does look like bronze or copper. notice the bluish molds on it?
but i'm maybe wrong

Yes the greenish thing indicates its not a gold, could be a copper or brass.... Just an opinion.

[ghost]

Ok if you don't want it tested on a pawnshop, if you have nitric acid, drop a little bit on the said metal. If the acid corrodes or 'eats' it, it's not gold but ordinary metal but if it turns it more shinier than before then there is the possibility of having gold content on it. Post the result.

[ZOBEX]

Go to a local store and get some acid drain cleaner, very common there.  Either nitric or hydrochloric acid type.  Put some in a glass jar or container and add equal amount of water, put in the object.  Wait.  If the object turns a bright pink, it is brass, if it turns a golden yellow, it is valuable.  Check the colors after removing the object and washing in running fresh water.  Brass alloy is a mixture of copper and zinc, the zinc is fine particles in the copper.  The acid will only penetrate the surface and will dissolve out the zinc leaving only pure copper in the surface.  Copper is pink, zinc is silvery white.  So the pure copper surface turns pink.  If you leave it out in the air, the copper will react with oxygen in the air and turn a dark brown color, copper oxide (there are several forms of copper oxide, one is black, copper hydroxide, picking up water from the air or what ever, is green).

Z

[wacky22]

tnx for the comment..what is it mean,,the color of the stone turn into brown..i have put some acid..thats the result it turn into brown..sorry for not posting a pic..

[ghost]

Then maybe copper alloyed with other metals. Read Zobex post, turning it brown when immersed to acid solution then exposed and oxidized by oxygen in the air thus results copper oxide (the color brown). Maybe it's really copper.

[La Asturiana]

Go to a local store and get some acid drain cleaner, very common there.  Either nitric or hydrochloric acid type.  Put some in a glass jar or container and add equal amount of water, put in the object.  Wait.  If the object turns a bright pink, it is brass, if it turns a golden yellow, it is valuable.  Check the colors after removing the object and washing in running fresh water.  Brass alloy is a mixture of copper and zinc, the zinc is fine particles in the copper.  The acid will only penetrate the surface and will dissolve out the zinc leaving only pure copper in the surface.  Copper is pink, zinc is silvery white.  So the pure copper surface turns pink.  If you leave it out in the air, the copper will react with oxygen in the air and turn a dark brown color, copper oxide (there are several forms of copper oxide, one is black, copper hydroxide, picking up water from the air or what ever, is green).

Z

Now I learn why the brass on a pistol belt and buckle turns dark brown after a few minutes from applying metal polish. It cannot maintain its bright pink color no matter how I polished it.

[AurumKid]

Now I learn why the brass on a pistol belt and
buckle turns dark brown after a few minutes
from applying metal polish. It cannot maintain
its bright pink color no matter how I polished it.


That's Oxidation, is the interaction between oxygen
molecules and other substances.

[ZOBEX]

Yup, copper oxide.  There is two kinds of brass polish.  One is chemical reaction and the other is mechanical polish.  But now days both kinds use a little of each way.  Mechanical polish is just dish pan scouring powder, its fine grit.  Chemical dissolves and loosens the surface chemically converted brass, that is oxide, sulfide and such.

If you have a yellow brass belt buckle and it is slowly turning pink with cleanings, then the acid in the polish is eating out the white zinc metal in the brass alloy leaving the pink copper exposed.  Not only that, if you use most of these kinds of metal polish, you should after wards scrub the part with soapy water and wash off the remaining residue of the chemically charged polish from the part's surface.  They dry polish with a clean rag.  Still it will eventually turn dark.  That dark oxidized but smooth surface is called " patina finish ".

Z

[wacky22]

very nice..i am very convince..beautiful explaination