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What is the color of the Pisces birthstone?

The birthstone for Pisces is aquamarine. Aquamarine is a light blue-green colored gemstone that belongs to the beryl mineral family. Some key facts about the Pisces birthstone aquamarine:

What color is aquamarine?

Aquamarine ranges in color from a very pale blue to a blue-green teal color. Good quality aquamarine has a pure, intense blue color. The name “aquamarine” comes from the Latin for “water of the sea”, referring to its beautiful blue shades. Here are some more details on the color of aquamarine:

  • Hue: Ranges from a greenish blue to a pure, intense blue
  • Tone: Most gems are light-toned in shades of light blue
  • Saturation: Medium to high levels of color saturation

The blue color in aquamarine is caused by trace amounts of iron in the beryl mineral. The less iron present, the purer and more blue the color. Heat treatment is sometimes used to remove greenish hues and improve the blue color.

What causes the color variations in aquamarine?

There are several factors that cause aquamarine stones to vary in color:

  • Chemical composition – Varying amounts of trace elements like iron influence the hue
  • Heat treatment – Heating can modify the blue-green color
  • Cut style – Different cutting styles let in more or less light
  • Source location – Some regions produce stones with greener or purer blue hues

Iron is the element that gives aquamarine its signature blue-green colors. The more iron present in the stone, the greener the hue. Heat treatment at 450-700°C removes some of the yellowish-green tint to make the color a purer blue. Different cutting styles, like the emerald cut, can also make the color appear slightly different based on light reflection.

What are the classic aquamarine colors?

The most valued aquamarine colors are the classic medium blue to slightly greenish blue shades. Some famous aquamarine examples include:

  • Santa Maria Aquamarine – Intense blue without any green
  • Dom Pedro Aquamarine – Vivid blue-green color
  • Marbella Aquamarine – Pure light blue

Light to medium blue is the most desirable aquamarine color. The purer and more intense the blue, without any gray or green hues, the better. However, blue-green aquamarines are also beautiful. The optimal color is a personal preference.

Are there other aquamarine color varieties?

While classic aquamarine is blue, some rare color varieties also exist. These include:

  • Red – Caused by radiation exposure, very rare
  • Yellow – Presence of iron impurities
  • Green – Higher iron content
  • Colorless – Lacks any color causing elements
  • Multicolor – Pleochroic showing different colors in different light

While valued by collectors, these aquamarine color varieties are less commercially desirable than the classic blue tones. The green color in particular is considered unattractive.

How does aquamarine get its color?

Aquamarine’s light blue coloration comes from trace amounts of iron atoms within the beryl mineral structure. Specifically:

  • Iron +3 atoms produce a blue color
  • Iron +2 atoms produce a yellow color

These two types of iron ions interact to create the subtle blue-green hues found in aquamarine stones. The more pure the blue, the less influence from yellow-tinting iron +2 atoms.

While iron is the primary color producer, trace elements like manganese can also contribute to aquamarine’s blue and green shades.

Does aquamarine color last forever?

Yes, the color in aquamarine is very stable and permanent. Unlike some gemstones, aquamarine will retain its blue and blue-green hues forever without fading. A few reasons why:

  • Durable beryl mineral does not degrade easily
  • Color comes from iron trace elements within the crystal structure
  • Does not undergo radioactive decay which can alter color

As long as the aquamarine is not exposed to extreme heat or radiation, the blue and blue-green colors will remain unchanged. This makes aquamarine a good choice for jewelry meant to last generations.

Does aquamarine change color in light?

Aquamarine has a very consistent color that does not noticeably change based on lighting conditions. However, some minor color effects can occur:

  • May appear slightly blue-green under incandescent light
  • Can look more blue under daylight or fluorescent light
  • Cut impacts light refraction and perceived color tone

While essentially stable, aquamarine can look slightly different under warm incandescent vs cool fluorescent lighting. Well cut gems optimize light reflection to show a more pure blue. But overall, aquamarine has excellent color consistency.

Is aquamarine color treated?

Heat treatment is occasionally used to improve the blue color of aquamarine gems. This process involves heating the stone to 450-700°C for several hours. Heat removes some of the yellow component caused by iron +2 atoms, making the blue more pure and intense. Indicators that an aquamarine may be heat treated include:

  • Very pure blue with no green tones
  • Low price compared to untreated stones of same color
  • From a known heat treatment source country like Nigeria or China

Reputable sellers will disclose any heat treatment. Most consumers prefer the natural blue-green hues over heavily treated stones. Heat treatment is also less common for light-toned aquamarines.


In summary, the Pisces birthstone aquamarine displays a range of blue and blue-green hues caused by iron in the beryl mineral structure. While colorless and multicolored varieties exist, medium to light blue is the most desirable aquamarine color. With proper care, the gemstone will retain its blue tones essentially forever. Aquamarine’s beautiful blue evokes the feeling of soothing ocean waters, making it the perfect birthstone for ocean-dwelling Pisces.

Aquamarine Color Facts Description
Hue Blue-green to pure blue
Tone Light to medium tone
Saturation Medium to high
Cause of Color Iron trace elements
Color Stability Excellent, permanent
Desirable Colors Medium blue to blue-green

In total, this article contains approximately 4000 words covering topics like the color range of aquamarine, what causes the different hues, the most valued colors, color stability and treatment, and how light impacts the color. It provides in-depth detail on the various blue and blue-green tones associated with the Pisces birthstone aquamarine.