與鑑定鑽石的4C標準相似，美國寶石學院有一個珍珠鑑 定七要素：形狀、尺寸、顏色、光澤、表面品質、匹配性及 珍珠層。珍珠的尺寸以毫米顯示，視乎品種而定。而珍珠的 品種很多，依它的母體牡蠣種類不同，有天然和人工養殖之 分，主要包括淡水養殖珍珠、Akoya養珠、大溪地珍珠及南 洋珍珠。這當中Akoya珍珠一般最為細小，尺寸通常在2到10 毫米之間，南洋珠較大，介乎8至20毫米。當其它因素相等 時，同類型的大珍珠比較小的珍珠更為稀有，更有價值。 顏色是另一個重要的方面，珍珠的整體顏色稱之為「體 色」，同樣由牡蠣的種類決定，主要分為冷、暖色調，範圍 從白色、金色、粉紅色、綠色到紫色。如果要尋找最白的珍 珠，海水養殖的日本Akoya珍珠通常名列前茅。 對於珍珠不太瞭解的人來說，珍珠母貝可能是一個陌生 的術語，其實它就是最常被提及的「珠光」——其表層下的 閃動彩虹色。珍珠母貝決定了珍珠的耐久性和光澤，一般來 說，層數越多越好。光澤被視為珍珠價值七要素中最被看重 的因素，反光越明亮、越銳利越好。此外，圓潤的珍珠比多 皺紋和凹痕的珍珠品質更好。 至於形狀，大多數人認為珍珠是圓形的，其實，圓形是 最難培育的形狀，因此渾圓的珍珠最為最稀和名貴。不過， 形狀不錯的橢圓形珍珠、形狀奇特的珍珠也備受推崇。 Compared to the “4Cs” of diamonds, the nuances in selecting pearls is more complex. According to the Gemological Institute of America, the seven classification values are size, colour, nacre and surface quality, lustre, shape and matching. SIzE There are a number of different varieties of pearls, based on the type of oyster in which they are produced, and they can be natural or cultured. Different varieties tend to have different sizes. For example, Akoya pearls are generally smaller, ranging from 2 to 10 millimetres, while South Sea pearls are larger, ranging from 8 to 20 millimetres. When other value factors are equal, larger pearls are rarer and more valuable than smaller pearls of the same type. Colour The next criteria is colour, and there are three components: the overall body colour, the overtone and the orient—which is the iridescence on or just below a pearl’s surface. Again, a pearl’s colour is determined by the type of oyster. They are generally divided into warm and cool tones, with a colour range of white, gold, pink, green and purple. If you are looking for the whitest pearls, saltwater-cultured Akoya pearls tend to top the chart. NACrE & SurFACE quAlITy Nacre may be a foreign term for those foraging into pearls for the first time. Commonly referred to as mother-of-pearl, it refers to the iridescent layers that a pearl is made of. It determines the durability and the lustre of the pearl—in general, the thicker the better. luSTrE Speaking of lustre, it is seen as the most important among the seven pearl value factors, and it is evaluated based on its reflection—the brighter and sharper the better. Also, a pearl with fewer surface irregularities is seen as better quality than one with many wrinkles and dents. ShAPE As for shape, most think of pearls as round, but it is actually the most difficult shape to culture, making them the rarest and most valuable. however, well-formed pear or novelty shapes are also highly regarded. 四種珍珠鑲嵌工藝 Four SETTING mEThoDS 插鑲 DrIllING 爪鑲 ProNG SETTING 包鑲 bEzEl SETTING 繞鑲 WrAPPING 一件珍珠首飾的整體價值往往通過珠寶設計師在作品 中藝術運用珍珠的顏色、形狀、大小，以及所使用的鑲嵌方 法體現出來。珍珠的鑲嵌方法很講究，要盡量保留珍珠原貌 與光澤。鑲嵌工藝主要包括：插鑲，將圓形珍珠打孔後，用 焊接的金屬針來固定珍珠；爪鑲，將珍珠鑲嵌在爪托上，有 二、三、四、六爪之分，珍珠的遮蓋面較少；包鑲，用金屬 邊把珍珠四周包圍住；繞鑲，以金屬線將珍珠纏繞起來，多 用於異形或巴羅克珍珠。 mATChING When featuring multiple pearls, the overall value of a piece can lie in the jewelry designer’s artistic matching of colours, shapes and sizes within a piece, as well as the setting method used. Some common setting techniques are drilling, where a metal needle is used to secure pearls after they’re drilled; prong setting, where pearls are set on prongs with options of two, three, four or six prongs, allowing minimal coverage of the pearl; bezel setting, where a metal rim surrounds the pearl; and wrapping, where metal wire is used to wrap around the pearl, often applied to irregular or baroque pearls. E L I T E G E N • S u mm E r • 2 0 2 4 51
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