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Are platinum and white gold equally prone to scratches?

StoopidMonkey

Shiny_Rock
Joined
Mar 11, 2011
Messages
127
I've seen a lot here lately about people getting dismayed when their platinum jewelry scratches or patinas with some wishing they had gone with white gold. Thing is, and correct me if I'm wrong, isn't white gold (or any 18K gold) just as prone to scratches as platinum is? If we're going by Vickers Hardness, here's what I'm seeing:

•18K Gold = 125 HV
•Pt900/Ir = 110HV
•Pt950/Ir = 80HV
•Pt950/Ru = 130HV

Apart from the notably less scratch resistant 950/Ir alloy, it seems the other common platinum alloys are in the same ballpark of hardness as white gold. Going by the numbers, the conclusion I come to is that all noble precious metals used in jewelry are susceptable to scratching, and the only way around it apart from frequent polishing is to opt for a less expensive "modern" metal such as tungsten carbide, which isn't seen in many lady's rings since they typically can't be cast, only machined (as in men's bands). Am I missing anything here?
 

oldminer

Ideal_Rock
Trade
Joined
Sep 3, 2000
Messages
6,450
You are oversimplifying, but basically correct. A great deal of effort goes into adjusting the alloy mix to alter the characteristics of precious metals. They can be harder than expected or softer depending on the choice of alloys and how the heating, cooling and annealing processes are done. Most precious metals are of interest because they are readily engraveable, meaning that they would not be so hard that one can't carve or scratch them quite a bit intentionally to create a design or a surface finish.

SOme of the new metals are far more durable, but way less capable of being turned into ornate jewelry. They may be the perfect mateial for plain shapes and simplicity, but not nearly as good for complex creativity. Many societies consider GOLD as their wealth and savings, so exotic metals have no influence on their decisions about what to make jewelry out of. Most of us here consider jewelry as ornamentation and we can use most any material that works for the design. m I don't see anything wrong with either point of view.

Jewelry made in properly alloyed precious metal and made heavy and solid enough to withstand daily wear will last far longer than most individual owner's lifetime. We do see instances of metal alloyed too soft or items made too light or thin to be long lasting due to today's extraordinary cost of materials. It is good to look at alternative choices as well as the traditional precious metals.
 

CaprineSun

Brilliant_Rock
Joined
Sep 30, 2010
Messages
547
StoopidMonkey|1315398147|3011493 said:
I've seen a lot here lately about people getting dismayed when their platinum jewelry scratches or patinas with some wishing they had gone with white gold. Thing is, and correct me if I'm wrong, isn't white gold (or any 18K gold) just as prone to scratches as platinum is? If we're going by Vickers Hardness, here's what I'm seeing:

•18K Gold = 125 HV
•Pt900/Ir = 110HV
•Pt950/Ir = 80HV
•Pt950/Ru = 130HV

Apart from the notably less scratch resistant 950/Ir alloy, it seems the other common platinum alloys are in the same ballpark of hardness as white gold. Going by the numbers, the conclusion I come to is that all noble precious metals used in jewelry are susceptable to scratching, and the only way around it apart from frequent polishing is to opt for a less expensive "modern" metal such as tungsten carbide, which isn't seen in many lady's rings since they typically can't be cast, only machined (as in men's bands). Am I missing anything here?
Yes.
Yellow gold may have an HV of 125. But white gold-- often alloyed with nickel (& other metals), is *much* harder (also more brittle) than platinum at 225 HV for 18K white gold.

I love referencing this chart because it lays it all out there: http://www.hooverandstrong.com/category/Casting+Grain+Specifications/ Found it over a yr ago & still helps me.

Ultimately, with these metals, it comes down to which you prefer & which "downside" of a particular metal you're willing to put up with. I'm still trying to figure that one out myself. HTH.
 

StoopidMonkey

Shiny_Rock
Joined
Mar 11, 2011
Messages
127
Ah, I stand corrected then. Whilst Googling for it I ran into two places that insinuated that white and yellow 18K gold had the same Vickers Hardness. That spreadsheet looks a bit more credible.
 
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