Apple’s patent-pending 18k gold: Harder, more scratch-resistant, and ‘less gold’

Apple’s patent application is for a method that allows them to make 18k gold that has, on a volume basis, less gold than regular 18k gold,” Dr. Drang blogs.

“How can this be? It’s because Apple’s gold is a metal matrix composite, not a standard alloy,” Dr. Drang explains. “Instead of mixing the gold with silver, copper, or other metals to make it harder, Apple is mixing it with low-density ceramic particles. The ceramic makes Apple’s gold harder and more scratch-resistant—which Tim Cook touted during the September announcement—and it also makes it less dense overall.”

“The karat measure of gold is based on the mass fraction. One hundred grams of 18k gold has 75 grams of gold and 25 grams of other material. If that ‘other material’ is a low-density ceramic, it takes up a bigger volume than if it’s a high-density metal. Because the casing of a watch is made to a particular size (i.e. volume), not to a particular weight, the Apple Watch will have less gold in it than an 18k case made of a conventional alloy,” Dr. Drang explains. “The patent makes it clear that saving gold is one of the goals of the process.”

More info and a bunch of math in the full article here.

Related articles:
Apple may buy 746 tons of gold per year for its Apple Watches – March 7, 2015

45 Comments

  1. Re kevicosuave comment earlier: Agree…

    As Apple stated from the beginning, “The Edition collection features six uniquely elegant expressions of Apple Watch. Each has a watch case crafted from 18-karat gold that our metallurgists have developed to be up to twice as hard as standard gold.”

    And, as describe elsewhere*, “Hardness is how we judge how easily things scratch. Some technical numbers show how a higher number scratches the same number and anything lower. Hardness is related to the Mohs hardness scale. Diamond is the hardest at 10. Talc is listed as 1 the softest. Pure gold (24 karat) is Mohs 2.5, 14 and 18 karat list at Mohs 3. Platinum list at Mohs 4.33. Sterling silver list at Mohs 2.5.”

    Not my expertise, but could one surmise that Apple’s gold/ceramic = 75/25 ratio, would yield a hardness scale for standard gold of Mohs 3 to ~6. That being the case, the amount of gold in the gold Watch would be half of what normally would be needed to achieve the current 18k standard?

    And perhaps, the Watch will be significantly less than what the pundits are forecasting?

    https://www.mygemologist.com/learn/care-and-cleaning/caring-for-and-cleaning-your-jewelry/

  2. I wonder if any Las Vegas casinos are running the over/under on how long it will take before Samsung’s Gear watch starts to look just like the Apple Watch?

  3. One of the drawbacks to wearing high-K gold jewelry has always been its softness. High-K jewelry wears off of the surface and is lost forever. 18k rings will thin out much quicker than 10k rings.

    This new process is going to take a lot of thought. The karat standard is one of the oldest and most respected standards in the world. It wasn’t long ago that they hung people in Britain for manipulating or falsifying the standard.

    With 18k people expect 75% gold by weight. I’m sure the gold standard folks (and competition bureau people) are going to examine what is being produced and sold. Even the mighty Apple will not be able to cleverly market gold. It will either be 18k or it won’t. Simple as that.

    1. I’d like to understand your point about apple’s challenge here. It’s really not at all clear to me.

      You seem to be implying that there’s somethin about this ceramic gold alloy that requires deception, or that deviates from accepted practice.

      If everything described in the article is true, then it would seem that apple is working completely within the rules of the road

      What marketing challenge r u talking about. Apple has apparently made an true 18k gold alloy that is twice as hard as is typical and which weighs less per unit volume than is typical. I don’t see any need for deceptive marketing here

      Could you clarify your point

      1. Better yet, how do you falsify the STANDARD?

        As far as I know…
        “The karat measure of gold is based on the mass fraction. One hundred grams of 18k gold has 75 grams of gold and 25 grams of other material. If that “other material” is a low-density ceramic, it takes up a bigger volume than if it’s a high-density metal. Because the casing of a watch is made to a particular size (i.e. volume), not to a particular weight, the Watch will have less gold in it than an 18k case made of a conventional alloy.”*

        In order for anyone to falsify the STANDARD would require them to STAMP the ‘GOLD’ (I.E., THE PART OF THE) item with a higher ‘K’ value than it is.

        As stated, “According to a new report*, Apple holds a patent that allows them to make 18-karat gold that uses just 28 percent as much gold (in volume) as a standard† 18-karat gold alloy.

        For consumers, this means that the pricing model for the Apple Watch Edition may be significantly lower than the original estimates. It is fascinating to see that Apple has some brilliant material scientists on board working on breakthrough manufacturing techniques.”

        † NOTE: Perhaps the area of confusion is likely the liberal use of the word STANDARD. For clarity, the author should have said, ” “According to a new report*, Apple holds a patent that allows them to make 18-karat gold that uses just 28 percent as much gold (in volume) as the usual 18-karat gold (all-metal) alloy made today.

        * http://leancrew.com/all-this/2015/03/apple-gold/

    2. You bring up a good point.. Till now the expectation of 18K gold was that regardless of the alloy used the deviation in weight was small due to the metals being used for the alloy being relatively similar in density. Now with Apple’s ceramic patent for a new 18k gold compound the weight may differ quite significantly. This is purely an emotional value but may cause the jewelry industry to reexamine the carat standard to account for the larger variation between the heaviest and lightest 18k compounds.

  4. The PATENT here: http://pdfaiw.uspto.gov/.aiw?PageNum=0&docid=20140361670&IDKey=A9058DEAFBAB&HomeUrl=http%3A%2F%2Fappft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO1%2526Sect2%3DHITOFF%2526d%3DPG01%2526p%3D1%2526u%3D%2Fnetahtml%2FPTO%2Fsrchnum.html%2526r%3D1%2526f%3DG%2526l%3D50%2526s1%3D20140361670.PGNR.%2526OS%3D%2526RS%3D

    What I found interesting was in the Background:

    “[0004] What is desired is a metal matrix composite that presents a cosmetically appealing appearance that is maintained throughout an operation lifetime and is relatively inexpensive to manufacture in both processing and materials.”

    Perhaps we will be seeing an Edition Gold Watch at <$2000?

    Great read. This patent could be literally a gold mine. Particularly as described using other metals with metal and non-metal materials

  5. Wow.. That’s pretty interesting.. So if you can somehow create a gold-aerogel compound you could have something that has less than 1 percent gold and over 99% aerogel and still be considered 18K gold.. 😛

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