Hi!
I would like to know what for a metal is this strange 18K white gold that comes as part of the blowing edqe of the b.hole in my Nagahara headjoint?

" White Gold

Because 18k white gold is 75% gold, and 14k white gold is 58.3% gold, jewelry made from these metals has a slight yellow color. To enhance the whiteness, almost all white gold is plated with rhodium, a shiny, white metal which is extremely hard. Depending on the amount of wear to a piece of jewelry, over time this rhodium plating may wear off, revealing the original metal color. Re-plating is a simple process that can be done to restore your jewelry's whiteness if needed. "
From:
http://www.bluenile.com/gold-jewelry/gold-education

Thank you.

The white-gold part of the blowing hole is indeed a little yellow when compared side by side with the .950 silver of the rest.

I hope this is not just Rhodium plated on 18K gold. Could it be possible that the 25% of the gold alloy be something more white (sp whither?) than copper? What could it be?

I think that the springs of the Yamaha 674 I have are also said to be made out of white-gold

I have found this in W:
White gold is an alloy of gold and at least one white metal, usually nickel or palladium. Like yellow gold, the purity of white gold is given in carats.

White gold's properties vary depending on the metals and proportions used. As a result, white gold alloys can be used for different purposes; while a nickel alloy is hard and strong, and therefore good for rings and pins, gold-palladium alloys are soft, pliable and good for white gold gemstone settings, sometimes with other metals like copper, silver, and platinum for weight and durability, although this often requires specialized goldsmiths. The term white gold is used very loosely in the industry to describe carat gold alloys with a whitish hue. Many believe that the color of the rhodium plating, which is what they see on many commercial pieces, is actually the color of white gold. The term white covers a large spectrum of colors that borders or overlaps pale yellow, tinted brown, and even very pale rose. The jewelry industry often hide these off-white colours by rhodium plating.

18ct (750) white gold is usualy a combo of gold palladium, copper, and silver

nickel as a alloy in precious metals is allmost never used as the chance of it reacting to people was quite high and with the new procedures in recovering paladium from ore made it a much better metal to use the other advantages of palladium as a alloy is the metal has a very bright white colour with out the need to rodium plate it and palladium-gold combo resists tarnish

18ct white gold is allso harder to work than any other precious metal

but in yellow gold 9ct (375) is the hardest and 18ct (750) is quite malleable

when its used as springs it is work hardened so it will spring back over and over again normaly you anneal precious metals to relax the crystal structure and make it pliable it allso stops the metal from cracking

white gold, red gold, green gold, and yellow gold all form naturaly typicaly gold found in new guinea is quite white compared to most other places usualy being 91% pure the remainder being a natural alloy with silver

Thanks.

Do you mean that the white gold part of the blowing hole is harder than the surrounding silver .950? It should be good news, in such a case.

yes the 18ctwg portion is much harder it would be aproximatley 3 times harder than the silver

the physical properties of both metals are totaly different to each other the WG is a much more dense metal and its crystal structure is more tightly packed than silver

allso if you had a wine glass made from both metals and you struck them with your finger nail the silver would have a light ring sound and the gold would have a dull thud tone.

i hope this helps

I does, thank you.