First, read the English article below.

Emeralds come in a range of colors.  Color is one of the most important factors in determining the value of an emerald.  The variance of color in emeralds is due to differing amounts of chromium, vanadium, and iron in the environment in which the stones formed.   Color can be subdivided into the categories of hue, tone, and saturation. Hue is probably what you think of when you hear the word “color.”  An emerald’s hue is its specific type of green.  Emerald hues can range from bluish-green to a more yellow-green. For example, Zambian emeralds are characterized by deep bluish greens, while Brazilian and Colombian emeralds often take on a rich, pure green hue. Tone refers to how light or dark the color of an emerald is.  Emeralds can range from very light green to very dark green in tone.  The association of tone and value is somewhat complicated.  Darker emeralds are often considered more valuable, but if an emerald becomes too dark, it becomes less valuable.  Emeralds with medium to medium-dark tones are the most valuable emeralds in the market. Emeralds with pure green or blue-green tones are the most desirable, in part because blue-green emeralds are associated with a very famous and highly-regarded gem mine in Columbia called the Muzo Mine. Be aware that emeralds that are too yellow or too blue may not be considered real emeralds and are therefore far less valuable. Saturation is tied to the gem’s transparency. Emeralds with high saturation (which means that they are highly transparent) are more valuable than emeralds with low saturation. Saturation can be tied to both inclusion and tone; very included gems can appear less transparent.  Similarly, very dark green emeralds do not absorb much light, so they appear duller than lighter emeralds. 

Now, please write a short abstract for it in Vietnamese. Abstract:
Hiểu sự quan trọng của màu sắc. Xác định màu sắc của một viên ngọc lục bảo. Nhìn vào tông màu của viên ngọc lục bảo. Đánh giá độ bão hòa của viên ngọc lục bảo.