cw0909 ,
None of the gold plating on most any electronic component is 10K, 14K, or 18K. The only exception I've seen is a Au/Pd alloy that was used for plating reed switches. I'm sure there are other rare exceptions, but these certainly don't include the parts in the photos. The plating on the ICs in the photo is most probably 99.99% pure (24K). Anything less would discolor when they are heated during the chip attachment or lid attachment (for the one with the gold plated lid, at least). Gold plated PCB fingers are nearly always plated with gold of at least 99% (23.76K) purity. For fingers, connector pins, or anything that could exhibit wear from multiple insertions, from .1% to 1% of cobalt or nickel is normally added to produce a harder deposit.
There are gold plating baths, used for decorative purposes, such as costume jewelry, that are called 14K, 18K, etc. However, the deposits from these only give a 14K or 18K color. In actuality, they are about 21 -23K. The color of plated gold is different than that of cast gold. With plated gold, it takes much less alloying ingredients to produce a pale color. Even with the addition of only 1% cobalt (99% gold), the plating will be noticeably paler than 24K plating, under the right light.
I'm curious where you got the idea that these parts are plated with 10, 14, or 18K gold. If an electronic tester was used to get this information, I'm afraid they are worthless for the determination of the purity of gold plating, unless it is very, very thick. The thickest gold plating you're likely to find on any electronic parts is about .0001", and I doubt if even that would qualify.