So lets talk about the metals...
We'll start with Gold, since this is the metal of choice that many Fine Jewelry pieces are set in.
When it comes to color, the metal of choice is really a matter of personal preference and gold certainly offers several options.
When we think of a Gold bullion bar, stamped or assayed with a designation of .999 , it refers to its content purity, also referred to as 24K gold. Since pure gold is fairly soft & malleable, a combination of other metal alloys are added when casting to help add durability and offer better wear as a piece of fine jewelry. The image below shows Karat & percentage of Gold content as it pertains to parts of 1000. or .999.
The Alloys & the blending of Color
Starting with the base metal of pure gold , a combination of silverish-white metal alloys such as zinc, nickel, silver & palladium are used to create White Gold. Once a piece is cast and finished, a plating of Rhodium is used in order to brighten the color of white gold. This coating also offers a little more hardness, scratch resistance and less oxidation to the piece.
The addition of Copper as an alloy along with other white metal alloys is used to produce Rose Gold. For example, 14K Rose gold will appear "rosier" (more copper percentage used in alloy) vs 18K rose gold will display a warmer Rose yellow undertone.
On to Platinum
Platinum is a true white metal, bright silver in Color, ductile and resistant to corrosion with a higher melting point compared to gold. The plus to using Platinum is that it requires no additional plating and very little addition of alloy. Platinum's density is slightly higher than Gold, so it tends to give a piece of jewelry more heft. For example the weight of a men's band in Platinum is going to feel slightly heavier than a band in Gold of the same size.
So how do we choose the appropriate precious metal for the piece?
14K/585 Everyday wear fine jewelry. The percentage of alloy added makes it harder & more durable, perfect for those with a more active lifestyle or that want to wear their pieces on a daily bases and not have to worry to much about scuffing, scratching or bending. Naturally, rings tend to get the most wear compared with pendants or earrings. This is also a good choice for White & Rose gold jewelry pieces.
Chains are also a better choice in 14K, especially for daily use with pendants.
14K is the most common fineness for gold jewelry in the US and a more economical price point.
18K/750 For those that are looking to have more of a saturation of the Gold color in their pieces along with a higher gold content, 18K is a great choice. Aside from the warmth in color, this is my personal favorite (from a fresh off the bench perspective :)) to work with because it offers just the right amount of softness for setting more delicate stones with the right amount of balance for wearability. The higher yellow color also provides great contrast when nesting colored stones! Although it does require a little more care compared to a 14K gold jewelry, overall, throughout the years, it holds up very well. 18K is the gold standard of fineness for Jewelry production in many of the European countries.
22K/916 The color in 22K fineness is going to give you the closest look to pure gold, the yellows of the yellows, the highest content of gold for a wearable piece of jewelry. A little more Tender-Loving-Care is required with use because it has very little addition of alloy, but overall a beautiful, buttery rich look in color. Several of the Asian countries use this fineness for their gold pieces.
Plat. 950 Platinum is a wonderful choice if you are looking for a true white metal, without having to worry to much about the maintenance of Rhodium plating over time and you don't mind a little bit of additional weight on the finger. Another useful alternative for using platinum for engagement rings or mens bands is if you've had any known allergies in the past when using *white gold. Pure Gold does not cause allergies in in of itself, but sometimes the addition of Nickel as an alloy, often added to produce white gold can cause an allergic reaction to those who are sensitive to it. The look of Platinum over the years develops a beautiful, natural patina.
If you are reading this, I wish you a beautiful Golden sunset. I hope this was helpful and certainly, if you have any more questions about what to create your next piece of fine Jewelry in, I would be happy to have a chat!