Platinum PT900 or PT950? So what''s the difference?

[chictomato]

Hi there I am looking at resetting into a platinum 3 stone ring with a centre halo. I was given a choice of PT900 or PT950. Does it refers to the platinum content? PT90=90% platinum? PT950=95% platinum?They are priced almost the same. Which is harder? My current wedding is PT900, should I just make do with the PT900? tks

 

[stone-cold11]

3. HARDNESS AND DURABILITY

In discussions about precious metals people often confuse hardness with strength, but they are not the same.

Hardness = HV

Often referred to as "scratch resistance," hardness is measured using the Vickers Hardness scale. This tests the hardness of a metal by pushing a pointed object into the surface with a specified load and gauging penetration.

Durability = PSI

Tensile strength, or durability is measured in pounds per square inch.

Comparisons

* 18K Gold = 125 HV…29,000 PSI
* Pt900/Ir = 110HV…55,000 PSI
* Pt950/Ir = 80HV…40,000 PSI
* Pt950/Ru = 130HV…66,000 PSI
* Pt950/Co = 135HV…64,000 PSI

Gold is harder than some platinum alloys and will resist scratches better. Platinum is almost twice as durable as gold, is more ductile has much greater longevity. For the body of the piece the differences are not critical. For the prongs they have implications: For instance, white gold prongs will break. Yellow gold prongs will bend more, as will platinum, but platinum prongs are more durable over time.

Depends on what is the alloy metal used. PT900 is 90% Pt but what is the alloying metal.

Common alloys are using Ru, described in this article. http://journal.pricescope.com/Articles/47/1/An-Overview-Of-Common-Alloys-Used-In-Jewelry.aspx

EDT:

Hmm.. somehow, double posted...

 

[stone-cold11]

Depends on what is the alloy metal used. PT900 is 90% Pt but what is the alloying metal.

Common alloys are using Ru, described in this article. http://journal.pricescope.com/Articles/47/1/An-Overview-Of-Common-Alloys-Used-In-Jewelry.aspx

If the metal used to alloy is Ir, I would prefer the Pt900.

3. HARDNESS AND DURABILITY

In discussions about precious metals people often confuse hardness with strength, but they are not the same.

Hardness = HV

Often referred to as "scratch resistance," hardness is measured using the Vickers Hardness scale. This tests the hardness of a metal by pushing a pointed object into the surface with a specified load and gauging penetration.

Durability = PSI

Tensile strength, or durability is measured in pounds per square inch.

Comparisons

* 18K Gold = 125 HV…29,000 PSI
* Pt900/Ir = 110HV…55,000 PSI
* Pt950/Ir = 80HV…40,000 PSI
* Pt950/Ru = 130HV…66,000 PSI
* Pt950/Co = 135HV…64,000 PSI

Gold is harder than some platinum alloys and will resist scratches better. Platinum is almost twice as durable as gold, is more ductile has much greater longevity. For the body of the piece the differences are not critical. For the prongs they have implications: For instance, white gold prongs will break. Yellow gold prongs will bend more, as will platinum, but platinum prongs are more durable over time.

 

[Richard Sherwood]

Date: 8/25/2009 9:11:17 PM
Author: Stone-cold11

If the metal used to alloy is Ir, I would prefer the Pt900.

I''m with Stone-cold on this.

 

[Mattcv]

Any idea what Pt alloy combination is used in Tacori rings?

 

[Diamond Explorer]

Just to weigh in here a bit.

950 plat isn't always more desirable than 900. There are many different Platinum alloys and each has a unique set of properties. I like 900 platinum/iridium for its brightness, hardness, and workability. Iridium is a pretty amazing metal in its own right. They say most of the Iridium on earth is of extraterrestrial origin, from asteroids and such crashing into the earth. When mixed into the alloy, Iridium helps make platinum hard and bright, exactly what you want in fine jewelry.

 

[Laila619]

Date: 8/25/2009 9:42:11 PM
Author: Mattcv
Any idea what Pt alloy combination is used in Tacori rings?

I actually e-mailed Tacori about this, and they said it's 950 Ruthenium Platinum. They told me that was the most durable Platinum.

Scott Kay and Tiffany use the same.