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settings experts - alloys?

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strmrdr

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Can you give us a quick rundown of the most common alloys and the pro and cons of each and where each is best suited for use.
I think it would be nice to have this information in one place for easy reference.
It seems to come up fairly often.
Both plat and gold mixtures.

Thank you in advance.
 

DavidEmslie

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There are differnet alloys for different jobs.
Some are good for there physical aspects, others for there asthetics.

No single alloy of anyting is a win all for all, they have differnet uses and functions, one one is better than another hands down for everything...it depends on the function, and your needs, there are so many thing to consider.


Anyway here goes

Silver - Good for lower end jewelry as it is less expensive, but very soft, it self burnishes but takes on an even white patinia in time when worn.

10k Gold - The lowest Common gold alloy, considered to not be gold in some places as the content is less than %50 gold, Its hard, it can tarnish a little bit. its lighter, and considerd a low end alloy,

12k The strongest gold alloy out there, half gold, and equal parts silver/copper, very hard for gold. Not commonly used exept as an overlay on gold filled jewelry aka real junk.

14k The most common mid grade alloy out there, Its the norm in the US it holds up well but has a higher implied value than 10k, most Americans like the color. Its the most common for decent quality jewelry

18k Considerd high end in the states, its 75% pure a richer color, and softer metal.

20k 22k and 24k very soft, almost pure or pure, deep rich color, too much for most americans, most folks think its plated or costume jewelry
Its the norm in South East Asia and other places in the world and is usualy smithed into some amazing works.


White alloys,

there are two kinds of white gold, Nickel based and palladium based. Some people can react too the nickel based allows, the Palladium is the only legal alloy in Europe, its a few grams more expesnive, about the same cost as 18k it also self bunishes and keeps a polish. If nickle white gold is not cast at a very high temp it can have some yellowing in the grain and polish as an overtone.

platinum alloys.

You will hear alot of mumbo jumbo about platinum and the numbers that can be associated with it can be as confusing as the diamond charts at first. Depending on the alloy its great for some applications...and lousy for others. Its main drawbacks are the price and fact that it is a (NON-Self burnishing metal) this means every scratch that you get in it will stay there and not work out. making fora dull ugly grey look in time. The alloys have bene getting better in avoiding this effect for some time, however its high maintanance if you want it shiny.

Titanium

Its strong...its light, its touch, it stays shiny for a long time...but it cant be sized much and can not be worked traditionaly, only good for bands, my bet is that it will be a fad metal with as many people as I have seen who get bored with them after just a few months or couple years.

There are some exotic metals as well, but they are uncommon enough that unless you know you want someting in them or with them you would have to come to a true metal smith jeweler who is able to either make them or work with them. I call them PITA metals (Pain In The Ass) mainly becuase some of them are very touchy or have some aspects too them that are just weird to work with and in.
 

elmo

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You can't leave us hanging like this David
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...now please list the PITA alloys like the common ones above, along with what makes them cool as well as hard to work with
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.

I've also wondered what gives different gold alloys different hues, such as the red and green gold used in some mokume gane.
 

Griffin

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Yellow gold we are all familiar with is alloyed to various degrees (.585, .750, etc), but the alloying metals are roughly the same - primarily equal parts copper and silver.
A 50/50 copper/silver mix of alloy creates yellow gold.
If you put in a 60/40 copper/silver mix, you get red gold.
If you put in a 40/60 copper/silver mix, you get green gold.

If you melt red and green gold together, it does become yellow gold. These are slight oversimplifications of the alloys used, but generally correct.

White gold has a number of preparations, the primary differences are whether the alloy has a nickel base - the standard in the US still, or a Palladium and Silver base - fairly new here. Palladium white is now required for retail jewelry in EU countries and some parts of the world.
It is newer, and slightly more expensive, but it has many advantages. It is non-allergenic, easier to work in mass production without porosity, and is more grey-white of an alloy - so although not as white as platinum, it does not require plating to keep good color.

Platinum I think I will leave to someone more expert in handling it in a casting environment.
I do know .950 is a requirement in some world markets, meaning 90/10 is not as common anymore.
I also understand that there is no one "superior" alloy. Platinum is a fairly intolerant metal to cast, and various alloys have different properties requiring thier use in different types of rings.
For instance, Ruthenium can't be used in metal molds or to cast filagree well, but is supposed to be a wonderful metal to work otherwise.
Cobalt is popular for manufacture, as it can be used in metal molds, and even when it isn't you get less surface roughness requiring less polishing loss.
Iridium is supposed to be able to cast into almost anything wonderfully, but it is as soft as sterling silver.

There is much more to Platinum than this but I will leave that to someone else.
 

strmrdr

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Thank you David and Griffin I learned a thing or 4 :}
one question.

Is there a strenth\hardness difference between yellow/red/green gold of the same k rating?
 

strmrdr

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btt
 

DavidEmslie

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There are some differences in hardness, but it is not very noticeable. The hardness comes in when what is called work hardening or heat treating the metals. This can be done in several ways, normal wear will harden a ring every thime you bump it, your alineing the molecules a bit at a time.
For most special alloys they require custom making/casting, for the most part custom jewelry is made a quite a bit more sturdy/larger/beefy so the hardness is not as much of a matter.

As for the PITA metals...most of them are not used commonly at all, some of the Mokume gane metals are Shakudo (copper 94% and gold %6)+/- a couple %
Shibuishi can very a lot, its a copper silver mix, usualy 60/40 to 40/60
Kuuomido is copper with %1 arsinic in it,
Silver arsinic for a grey, I dont work with it for obviouse reasons
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Cobolt can be added to the molten mix to harden most metals when liquid.

Aside from that there are a few other odd ball alloys out there like Neillo, its a sulfer and lead mix and some other stuff, I cant find my reference book off hand with the recipe...but I dont make it either.

Gold can be purple if you mix it with aluminum in the right conditions...but its brittle...like penut brittle and breaks easy. I wont work in it
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You can get some weird alloys in dental alloys, mixes of gold and plat, with palladium, copper, silver ect.

Also melting natural nugget gold can have some weird colors. as the natural alloys vary sometimes from stream to stream, old miners that were good could reconize nuggets from a particular creek by color in some regions.

Silver does not tarnish if you add a bit of germanium...but 1 in 20 people will react too it...its weird.

There are a lot of alloys out there, some are good for wire/sheet, others for casting, others for color, others for name your need
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I am not an expert in all of them, we just use quite a few of them in our production, I alos dable a little bit in refining of metals as with the production of things like mokume the ammount of wast is insain, so its worth while with the volume we do to do in house refining and recycleing.

before I went into the jewelry business I was going to be a metals or materials engineer...looks like I ended up doing alot of that anyway
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If you really want to get all the knowlage you can about it Id recomend the compleat metals smith, its a requirement for any college jewelry class to have, I think its like $12 and has a wealth of info in there.
Aside from that just lots of R&D online, variouse books ect. Over the years you pick up some neat tricks and info about the whole mess, I could go on forever but my fingers are about to be worn off from typing and I am have to go take care of some things in England day after tomarrow and need to get packed
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Hope this info is useful.
 

strmrdr

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btt with some info I found on Platinum alloys:
source:
http://www.diamondsunlimited.com/platinum_alloy_mixes.html

The most common available in the US are Iridium, Ruthanium,Cobalt and Palladium alloyed with the platinum.

Hardness:
Plat %, Fineness, Melt/C, Hardness
Pure Platinum, No Alloy Added, 999, 1773, 50
5% Copper ,950 ,1725 ,120
5% Cobalt ,950 ,1750, 135
3Cobalt/7% Palladium, 900, 1730, 125
5% Cobalt / 10% Palladium, 850 ,1710, 150
1.5% Indium /3%Gallium ,950, 1550 ,225
5% Iridium - Used a LOT at Low price internet sites!, 950, 1780 ,80 / Soft!
10% Iridium / My optional mix, 900 ,1780 115
5% Palladium ,950 ,1755, 60
10% Palladium, 900 ,1750 ,80
15% Palladium ,850 ,1730, 90
5% Ruthenium , 950 ,1780, 135+
5% Tungsten, 950, 1830, 135
Plat-S-1™ ,950 ,,135-280
 

mazza

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Why, oh why, is it not the case that the alloy metals used with a primary metal do not have to be indicated on jewellery?? Surely the consumer should be entitled by law to know exactly what an object is fully made of! So, why not say 'Pt950/Ru50' for a piece which is 95% platinum and 50% Ruthenium, and so on?!?
saint.gif
 

antigoon

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I've seen a lot of talk on this forum stating that palladium white gold alloy is much whiter than nickel based.

But I'm still confused. On another thread, somebody pointed to this link describing the various 18k/19k white gold alloys. So I've got some questions for David, or other jewelers:

1. When you say palladium and nickel, which ones do you mean? Palladium is in OB 1,5,11. But they contain more silver (OB1,5) or copper (OB11) than palladium. Nickel is in OB18, 19; but they also contain more nickel.

2. All palladium alloys do not look the same.
Looking at table 2, "...an alloy exhibits a beter white colour whn C tends to 0"
OB11 is very white while OB5 is in fact quite yellow, and OB1 is somewhere in between.

2.1 When a jeweler is using "palladium white gold", are they always using OB 11?


Steve

Boy oh boy. My fiancee to be had better appreciate the research I'm doing. LOL
 

PhillipSchmidt

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Platinum alloys preferences IMO.
My opinions are based on what I have seen; what alloys, by average, have exhibited which properties.

There is no perfect alloy. They all have useful properties. The metals used to alloy are not usually added at 100%, but alloys themselves and different combinations yield different results.

Some variances are: casting results: (porosity, finesse, and polish ability), workability/malleability, colour, fusibility and weather it can be re-melted/refined without expensive dedicated equipment, hardness and how well it polishes and how well it keeps its polish.

Cobalt is the most common casting alloy and the results in castings are excellent. It is bluish and it oxidises, but it takes rhodium better then gold alloys and the oxidation can be removed (though not with sulphuric acid). It has a good hardness, fairly workable (though you would never use it as stock gauge metal for hand wrought pieces). It is difficulty to refine. It does not overtly soften by annealing and does not ''work-harden'' very much. The hardness is therefore relatively stable, which suits is mass-production purpose. It lacks good colour. Cobalt is a heavy metal making 950 platinum, less platinum by volume, but it is a decent alloy and for cheaper jewellery, therefore it is a good bet.

Iridium is the best and worst alloy, with the best colour and a liquid platinum finish in harder alloy varieties. Plat 950 and pure iridium is terribly soft. What is worse is that it becomes very soft after annealing (heating). It shouldn''t be sold. Plat 900 is perhaps the best alloy. Plat 950 with some other Plat group alloys in the mix (which I have more personal experience with), is extremely white, it polishes well and keeps its polish well because it is hard, it is extremely workable and hardens well with hand wrought techniques, known as ‘work-hardening’. I prefer this metal to all others, but it does soften with heat and may need to be hardened by burnishing (hitting it with a hammer etc), and plannishing (polishing with tungsten bits etc). It also will harden over time and a few days make a lot of difference. It is one of the best metals for hand wrought pieces and fine wires can be polished to extremes and be malleable and hard, offering a lot of scope for a smith wanting fine results. Unfortunately, I know of only one place that sells this alloy.

Ruthenium is the hardest alloy. It takes a lot to polish. I have never seen it produced in Australia and I think it is becoming rare. It takes an eon to polish and is not often cast well as it is prone to porosity. The finish is not as high as most alloys because of poorer casting on a microscopic level, but it will retain a good polish very well. It is greyish in colour. I am not sure if it is ever used in hand wrought pieces, as it is never offered in stock gauge (raw material) and perhaps it is too brittle for that. It must be refined professionally. It is hard but it is only ever cast so it is a bit limited when strength is the priority. Its main weakness is the time it takes to polish. The trade in general don''t achieve the best results due to the extra time needed. It averages approx'' three times as long to polish.

Copper is the most common metal for stock gauge. The vast majority of wedding bands are made from this alloy. It is used for hand wrought pieces. Though cheap to make, it is as good a metal as any for its purpose. The colour is not reddish at all. It takes an excellent polish. It can be fused and it is very malleable. It is not as white as an alloy with more iridium, but is almost every aspect it works as well as the iridium based platinum group metal alloy, which I prefer. It hardens very well by hand forging, perhaps that is in a direct correlation with its malleability. That is, in working the metal, a grain is worked into the structure of the metal. This is true of all precious metals. Many cast metals won''t polish very well.

Very often metal from one bullion dealer of the same kind differs to metal from another dealer and the same suppliers might have variances in their own metal over time. It is important for us to keep them informed. Moreover send any alloy less then their best alloy back for a new batch.

There are more alloys in use, but these are the ones I know best.

Phillip
 

freaknyea

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Why is it that some companies only offer 18k white gold. Let me know if I am wrong but 18k white gold will turn more yellow than 14k. My personal choice is to have a very shiny white metal. And not something that will ever eventually be dull like Platinum.
 

Jr22

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Platiumsmith,

I have a PLAT 950 wedding band, could that be melted down and made into another ring like you can do with gold? Since it is already a PT950 mix (I don''t know the 5% alloy) does it have to be made into another PT950 ring or can it be made into a PT900 ring to strengthen it if the 5% is Iridium? If it isn''t Iridium? It is a very heavy ring which leads me to believe it might be cobolt but I don''t know.

Is this a difficult process. I haven''t asked a local jeweler yet if this can be done I wanted to get your opinion first.

Thanks!
 

MissAva

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Date: 3/14/2004 2:50:51 PM
Author: DavidEmslie


Silver - Good for lower end jewelry as it is less expensive, but very soft, it self burnishes but takes on an even white patinia in time when worn.
I dont think Silver is only for lower end jewelery.
 

PhillipSchmidt

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Freaknyea,

W/G doesn''t turn yellow. It stays the same colour, but the plating wears off.

Yellowish W/G is found in the cheapest W/G in my experience. It is rare in rings. Most white gold is greyish where palladium is used, and whiter for more nickel. It wears faster then plat, but by scratching, whereas platinum dints/compresses because it is harder (in regards to scratching).

Jr22,

I personally would not attempt any of those things. I would have it refined and the return would be about half for new metal. If the alloy is known, it is possible. If your alloy is too soft then it may be iridium. Refining platinum is not easy and requires specialised equipment, not used in gold refining. Some jewellers specialise in refining platinum on a smaller scale, & they are cheaper then large refineries, returning stock gauge for a charge, but experienced metal smiths who are highly skilled in refining gold etc still farm this type of work out. I have concentrated on working with a plat alloy that can be refined more easily and so I will not mix it with another alloy. I have as much as 10 rings (in weight) of little bits of scrap that I will melt but I am waiting until I have more to make the effort worthwhile for me.

If it is cobalt it would be bluish, but that is about all. All alloys would feel about the same weight in your hand. All are heavy. I doubt you can mix cobalt alloy platinum with iridium to get a better result. Cobalt is not too soft. I don''t know if you would achieve a good result. I believe that some jewellers will melt cobalt, but I have yet to create a useable alloy in the two times I have tried because it went brittle. I know more now and am equipped better to try again, but my cobalt scrap is mixed with other alloys (I keep different plat alloy scrap separate). I wouldn''t like to work with the result, even if it could be worked. The resulting piece would not be as good as clean bought alloy and it would take a lot longer, so the refining route would be the cheaper option at any rate.

It may be worth asking your jeweller what they are prepared to do. I have never heard of a jeweller offering that service, but some will refine 50grms etc for the trade. I work in amongst my local jewellery making centre. If I was working away from here I would have had more recourse to test platinum melts. If your jeweller doesn''t have easy access to the wider trade, bullion dealers, refiner’s et al, then he/she might be eager to try it.
 

PhillipSchmidt

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Mata,

It is so cheap that no matter what you do with it, it is hardly likely to become an expensive piece so your time has been wasted. That is my experience.

I have seen high prices for design led jewellery in silver with ''contemporary'' design and because the bullion is so cheap the profits were huge. It is considered that people don''t expect silver to be as cheap as it is, so they will pay more for a weighty silver jewel in certain circumstances. Students and designers use it to show off their craft because they can afford to make hundreds of pieces and get their name out. Additiionally, a lot of people don''t like gold/platinum design because it is too light weight and there are far less designs on offer in the shops, simply because the investment into untried designs is far too high.

It wears fast but this might not bother somebody wanting a bespoke/contepory piece where you have a the mass.

High quality silver design is sold by brand. Without a contemporary name, producing high quality silver jewellery is not profitable, as the market is otherwise awash with cheap mass-produced silver jewellery and this is what your product is compared with IMO.
 

freaknyea

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Platinumsmith... So what do I want to look for in White Gold... Example Cheap white gold vs. nice white gold. What questions should I be asking if I am searching for a white gold ring and what should I expect. Thank you. Chris
 

skog

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you say the 95%plat/5%irid should not be used in any jewely but this is what vatche uses I believe. Does this mean we should avoid vatche rings because of the softness?
skog
 

strmrdr

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Date: 8/29/2005 8:33:51 PM
Author: skog
you say the 95%plat/5%irid should not be used in any jewely but this is what vatche uses I believe. Does this mean we should avoid vatche rings because of the softness?

skog


http://www.diamondsunlimited.com/platinum_alloy_mixes.html


"Many use 950 Platinum with Iridium (IR) It is only 80HV on the Vickers hardness scale. 950 Platinum with Palladium is even softer. It is only 60HV. This super soft alloy can be found at some of the biggest jewelry sites on the net."
 

skog

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I read the article. I was just wondering what people personal prefrence was this the 95%plat/5%irid alloy. does this alloy work harden well? I heard from a local jeweler that that petucular (sp?) alloy is actually very good. He said the inside stay soft so it is durable but when you polish it the surface hardens and holds a good shine and wont dent easily. How true is this?

skog
 

PhillipSchmidt

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Go for paladium W/G. It is a lot more expensive, but it is a very nice metal. It is greyish white. The paladium content will only be from, 12% - 16%. Other alloys can bring the colour up. There are non-paladium alloys that are whiter. I don''t refine my own alloys. I don''t mass-produce anything so I don''t have the bulk to warrent mixing my own alloys to save a few cents. Sorry I think I am not much help.

I was wrong about the nickel, being white. It is yellowish, yuk.

I have to admit that I try a lot of white gold alloys and I know which ones I like, which are very white but not as white as platinum. The best I use has 12.5% paladium and it is rock hard. It polishes extremely well without much waste and it is very nice to work with.

I am funny about my alloys probably because a lot of my early years were spent refining gold alloys and the over-used metal was really poor and not worth the effort. When I worked in the UK, nothing was re-melted due to fear of failing the mandatory assay testing. From then on I have rarely used refined metal, because I am now too spoiled. I am interested in knowing more about the necessesary properties but admitedly a lot of jewellers know more then me.
 

freaknyea

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Platinumsmith... For the sake of me now knowing much about metals at all you said to use the paladium white gold. Is that in any gold as in 18k vs. 14k... or there is more in one than the other? Thanks Chris
 

PhillipSchmidt

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We don''t use 14k here, only 9k or 18k and 9k here is for cheap jewels. As I work by hand I can''t use it. Saying that, I think the same applies to a degree. I would rather suggest, if you want better go for 18k. I am sure there are nice 14k alloys out there, but I don''t know anything about them, sorry. If it is about price, then buy from what you can see and look around for quality - here I can help. It is no easy task. People don''t talk about paladium 9k W/G very often though I am sure that there are some who prefer to offer it and 14k moreso.

Sorry I can''t help.
 

PhillipSchmidt

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I posted this just now in ''Rocky Talk'' but I want to add it here also because I think it adds a bit to the growing knowledge base. Sorry if it is a bit long.

Some practical experiences I have had with ruthenium alloyed platinum.

It starts with a background...

I worked as a diamond setter, assembler, etc in the UK for the trade. The area that I worked in has more then 2500 jewellers. I often set diamonds and polished ruthenium alloyed platinum. I saw a lot of other platinum jewellery with other alloys.

One casting house that we often used produced a ruthenium alloy. They had periodic problems with porosity, but they had a laser welder at call, so if the porosity didn''t show until too much work had been done, it could be fixed. The porosity problem was worse then most other casting houses - using other alloys; better or worse, but the good service made them a good choice regardless.

The ruthenium castings were always rough and we expected that it would take a lot of filing to get the right form. I was working on a high turnover and I typically produced hand carved waxes & waxes produced by CAD CAM. I made my designs heavy, expecting to refine the design in platinum. (Nowadays, I cast a wax in silver and perfect the design before I make a mould and this extra step ensures the casting will be exactly how I want it to be and I get better results here then I had before). Casting a wax can create a lot of waste in platinum.

I used to work with ruthenium quite a lot. The castings were relatively poor, but that metal was viable in my situation - see above. I must admit I did like the hardness and it was good for that reason, though I can’t say I had a chance to alter my designs to use the extra strength, because the castings were so bad. I understand that they were not getting the investment right (casting term, don''t worry) and the castings should have been better, so perhaps somebody, somewhere is casting; fine 4 claw settings in ruthenium, which can’t be done in other alloys, but I don’t know about that. I suppose if you are that fussy, then you should go for hand wrought manufacture and pay the extra for the increased labour and waste. That is, if the absolute best results are wanted.

Personally I like almost any good clean platinum stock gauge; say 6mm square wire - raw material.

If I had to choose a casting medium I would choose (not in this order) 900 plat + 100 iridium (safe bet for the average fussy consumer), or a good 950 plat + (e.g.) 20 iridium + ruthenium + rhodium etc – quantities and methodology unknown (though the 950 stamp is a good thing), and then cobalt, then ruthenium (done properly) & you can probably discount the rest.

I prefer platinum group metals to be alloyed together for best results, but then there is copper and it was the best alloy (for hand wrought jewels) available until recently. I have never heard of it being cast, but I dare say it is added to cobalt/ruthenium etc with varied results. Gold is added too, with poor results.

Metallurgy is not logical to me, but such are the laws of nature. I understand that all the studious people involved in the field of precious metals have the same problem and every discovery is made by trial and error and many platinum alloy successes are kept as guarded secrets, at least for now.
 
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