To evaluate the quality of an ancient jade artifact, one must consider: first, its age; second, its historical context; third, its material texture; fourth, its coloration and patina; fifth, its luster; sixth, its transparency; and seventh, its craftsmanship and design. Generally speaking, the older the piece, the better; the more illustrious and renowned its provenance, the better; the finer and more uniform its texture, the better; the richer, more vibrant, and more abundant its coloration, the better; the smoother and more lustrous its surface, the better; the higher its transparency, the better; and the more distinctive its craftsmanship and form reflect the characteristics of its era—the better. Of course, the fewer cracks and imperfections it has, the better.

The identification of jade artifacts involves three key aspects: First, identifying the jade material—determining the specific variety of jade used in the artifact; second, detecting artificial treatments—assessing whether the color of the jade or the patina (qinse) on antique jade pieces, or other distinctive features, have been artificially altered; and third, distinguishing genuine items from counterfeit imitations, including even synthetic replicas.

In ancient times, jade artifacts didn't have the bright polish we see today; instead, they typically exhibited a luster reminiscent of oil on the sleeve. That's why we say the more oily and lustrous a jade piece is, the better it is. However, this does not apply to jade artifacts that have just been unearthed or those that haven't undergone "panmo" (polishing and rubbing) after excavation—such pieces often have surfaces that have been eroded and thus lack any noticeable luster. Yet if they do display a luster, especially one resembling glass, then they are exceedingly rare and highly prized. In ancient times, achieving a glass-like luster on jade required either advanced polishing techniques or an exceptionally long period of time. The oily luster naturally present on the surface of ancient jade artifacts was referred to by the ancients as "baojiang."

The craftsmanship and forms of jade artifacts reflect the characteristics of their respective eras. From the Neolithic period through the Xia and Shang dynasties, the carving techniques were simple, unadorned, and robust, with thick and substantial vessel shapes. We cannot judge these pieces by today’s standards of craftsmanship. Due to their great age, profound cultural significance, and exceptional value, they stand apart from ordinary artifacts. During the Spring and Autumn, Warring States, Han, and Tang-Song periods—and beyond—jade carvings, when evaluated by modern standards, are equally impressive. Naturally, the finer the craftsmanship, the better; whether the forms are archaic or refined and elegant, what truly matters is that they achieve harmony and charm.

The quality of ancient jade artifacts is typically evaluated based on the factors mentioned above. However, some jade pieces, due to their extreme rarity and scarcity, often excel in only one or two of these factors, thereby becoming extraordinary treasures. Such pieces are commonly referred to as the "Four Uniques"—four exceptional treasures: First, natural nine colors; second, filigree carving; third, old-earth deep red; fourth, multiple types of patina.

“Natural Nine Colors”: This refers to jade materials used for crafting jade artifacts. Naturally, these materials come in a variety of colors; in ancient times, people often used the number “nine” to describe abundance. “Having jade with nine colors at home is worth more than a hundred taels of gold.” This vividly illustrates how highly ancient people valued jade materials that exhibited multiple colors. If such jade materials are further crafted into exquisite jade artifacts, today they would undoubtedly be priceless treasures.

“Thread-like Carving”: It means that certain ancient jade artifacts exhibit an incredibly exquisite level of craftsmanship. The intricate patterns and carvings feature lines so fine they resemble delicate silk threads—elegant, flowing, and utterly seamless, as subtle as a single strand of autumn hair. Even today, such craftsmanship would be considered extraordinarily sophisticated; how much more so in ancient times, thousands of years ago! Consequently, these pieces are exceedingly rare and highly prized—today, they’re virtually impossible to find, and naturally, they’re priceless treasures.

“Old-fashioned bright red”: “Lao tu” refers to ancient jade that has just been unearthed, or ancient jade that, after being unearthed, has not yet undergone “pan mo.” If such jade, upon excavation, already displays a dense, bright-red infiltration—commonly known as “he ding hong”—it is called “lao tu da hong” and is an exceptionally rare and precious treasure.

“Multiple shades of seepage,” In other words, if an ancient jade artifact exhibits multiple colors of "qin se" (a type of discoloration caused by long-term burial), and these colors are both vivid and harmonious, penetrating deeply into the jade’s structure, then such a piece is considered a rare treasure. On the other hand, if the "qin se" merely lies on the surface, it indicates that the artifact is relatively more recent in age, and thus its intrinsic value is lower.