Gold is considered a yellowish color. The exact shade can vary depending on factors like purity and the type of gold, but the characteristic gold color is within the yellow to orange color range. When describing the color of gold, terms like “golden,” “yellow gold,” “goldish yellow,” and “golden yellow” are commonly used.
The Science Behind Gold’s Color
The color of gold comes from the electronic structure of the gold atom. Gold’s electron configuration results in strong absorption of shorter wavelengths of light, like blue light, leading to the characteristic yellowish and reddish hues of gold. The actual color depends on factors like the thickness of the gold sample and purity.
Shades of Yellow Gold
The most common shades of yellow gold include:
– Golden: A vibrant, warm yellow shade leaning towards orange. Also called rich gold.
– Goldish yellow: A bright yellow shade, neither warm nor greenish. Also called lemon gold.
– Old gold: A darkened yellow-brown shade with subtle orange tones.
– Yellow gold: A medium yellow shade, not intensely golden or greenish. A standard yellow gold.
The depth of the yellow/orange color depends on the gold purity, with higher purity gold appearing more intensely golden yellow. Alloys with more copper tend to have warmer, reddish hues while silver alloys produce paler gold shades.
Effects of Impurities on Gold Color
Impurities in gold impact the exact yellow hue:
– Copper produces a warmer, orange/red toned yellow.
– Silver results in a paler, less saturated yellow.
– Zinc also yields paler gold shades.
– Nickel gives a muted green-yellow tone.
So jewelry gold containing copper alloy appears more golden orange, while silver alloyed gold has a light lemon hue. The purity of the gold determines saturation.
Karat and Gold Color
Karat measures gold purity on a 24 point scale. The karat rating affects the intensity of the yellow color:
– 24K gold is pure with a deep golden yellow color
– 18K gold has a rich golden yellow hue
– 14K gold has a lighter, orange-yellow tone
– 10K gold is paler yellow, towards the lemon end of the yellow spectrum
Higher karat gold has more intense yellow tones because of the higher purity and less diluting alloys. But even 24K gold can have slightly different shades depending on other trace metals present.
Gold Plating Color
Gold plated items have a thin layer of gold applied to a base metal like brass or silver. The plating alters the color from the base metal to a gold tone, but it’s often lighter or less saturated than solid gold pieces.
The plating thickness affects saturation. Thicker plating up to 5-10 microns provides a richer gold tone while thinner 1-2 micron plating has a subtle pale gold effect.
White Gold Color
White gold is an alloy of gold with white metals like nickel, palladium, or silver. It has a pale whitish metallic color instead of yellow.
The nickel alloy produces a soft pale grayish white while palladium and silver alloys yield a bright silvery white. White gold may be rhodium plated to enhance whiteness and reduce tarnishing.
Rose Gold Color
Rose gold is gold alloyed with copper. The higher copper content gives rose gold a soft pinkish hue. Common shades include:
– Reddish gold: A light pinkish orange tone.
– Pink gold: A rosy pink shade.
– Rose gold: A mix of subtle pink and pale yellow.
The copper content affects the intensity of the pink tone. Rose gold used in jewelry generally has a redder, warmer pink color while rose gold plating tends to look more subtly pinkish.
Green Gold Color
Green gold gets its color from silver, zinc, and sometimes cadmium in the alloy. The shades can range from a pale yellowish green to a deeper olive tone.
Silver produces greener shades while cadmium and zinc lead to more muted yellow-greens. Green gold was popular in the Victorian era but is less common today.
Purple Gold Color
Gold can also form intermetallic compounds with aluminum or gallium which yields a purple color. This purple gold is generally created artificially in a lab setting. The process involves heating gold powder with the other elements to form crystals exhibiting a vivid purple effect.
Blue Gold Color
There is also a form of pale blue gold created by alloying with indium. This yields an unusual bluish hue ranging from pale icy blue to grayish blue. However, the indium makes the gold very brittle so it is rarely used in jewelry.
Black Gold Color
Black gold refers to gold alloyed with black ruthenium metal to yield a dark gray or black appearance. It sometimes may also refer to 18K white gold rhodium plated to enhance whiteness. The deep grayish effect resembles black.
Unconventional Gold Colors
While unusual, gold can also be processed to yield other colors through advanced nanotechnology and thin film interference effects. These include:
– Blue: Interference effects
– Green: Nanoparticle sizes
– Purple: Nanorods
– Red: Colloidal nanoparticles
But these exotic gold shades require lab manipulation and are not found naturally in gold.
Conclusion
In summary, the characteristic color of gold is in the yellow to golden orange range. The exact shade is determined by factors like purity, alloy composition, and plating thickness. Traditional gold is available in a variety of yellow tones while alloys with copper or silver produce rose gold or white gold. Unconventional shades can be generated artificially but are less common. The inherent color of natural gold is a warm, golden yellow.
| Gold Type | Color Tone |
|---|---|
| 24K yellow gold | Deep golden orange-yellow |
| 18K yellow gold | Rich golden yellow |
| 14K yellow gold | Medium orange-yellow |
| 10K yellow gold | Lighter lemon yellow |
| White gold | Light grayish white |
| Rose gold | Pinkish orange |
| Green gold | Light yellow-green |
| Purple gold | Vivid purple |
| Black gold | Dark gray or black |