Now that we have gained some insight into the various types of pearls, let's delve further into our understanding of Cultured Pearls.

During the 19th century, the Japanese became intrigued with the idea of producing pearls and several individuals attempted to replicate the natural pearl formation process. However, it was not until the early 20th century that Mikimoto, often referred to as the 'Father of Cultured Pearls,' achieved success in cultivating pearls.

Types of Cultured Pearls

Cultured Pearls can be broadly classified into two types:

• Those cultivated in Saltwater
• Those cultivated in Freshwater

Saltwater cultured pearls are primarily formed through a process known as "bead nucleation." In this method, pearl farmers implant the gonad of the host mollusc with a nucleus made from a freshwater mollusc shell, combined with a small section of mantle tissue from a donor mollusc.

Cultivating freshwater pearls involves a distinct method compared to saltwater pearls. The majority of freshwater pearls are created without bead nucleation. Instead, they undergo "tissue nucleation," a process where a fragment of mantle tissue is inserted into a mollusc to stimulate the formation of a cultured pearl.

Value factors

When assessing pearls, there are predominantly seven factors that are considered for determining their value:

Size

Pearl measurements are typically given in millimetres, rounded to the nearest 0.5mm. Japanese Akoya pearls are usually spherical, ranging in diameter from 2mm to 11mm. South Sea Cultured Pearls from Australia are recognized as the largest among cultured pearls, generally ranging from 2mm to 20mm, with rare sizes surpassing 18mm.

Tahitian Cultured Pearls vary in size from 8mm to 17mm, while Chinese Cultured Pearls are commonly produced in the 6mm to 10mm range, occasionally reaching 13mm. Some Chinese Freshwater Cultured Pearls can attain sizes up to 16mm.

Shape

The pearl industry acknowledges seven standard shapes:

• Round
• Near-round
• Oval
• Button
• Drop
• Semi-baroque
• Baroque

Colour

Broadly speaking, colour consists of three components:

Hue – the fundamental impression of colour, for example, blue, green or yellow

Tone – the lightness or darkness of the colour

Saturation – the strength or intensity of the colour

Pearl colours exhibit three characteristics:

Body colour – the predominant overall colour of a pearl

Overtone – a translucent colour that emerges over a pearl’s surface

Orient – surface iridescence

Lustre

Among all the factors influencing value, lustre holds the utmost significance, distinguishing pearls from other gemstones. Lustre refers to the intensity and sharpness of light reflected from a pearl's surface. Nacreous pearls exhibit a heightened lustre, whereas non-nacreous pearls showcase a more subdued shine.

Surface

The surface quality of a pearl significantly influences its value, focusing on the outer layer's condition and the presence of blemishes. Smooth, blemish-free pearls command higher value, while imperfections like spots or bumps can diminish aesthetic appeal. Grading systems categorize pearls based on surface quality, ranging from flawless to those with noticeable blemishes, impacting overall grading and pricing.

Nacre thickness

Nacre thickness is a vital factor in pearl assessment, referring to the organic layers around the nucleus. Thicker nacre is linked to higher-quality pearls, influencing their durability, beauty, and overall value. Thin nacre can lead to less lustre and fragility, while thicker nacre enhances both lustre and durability.

Matching or uniformity of appearance

Matching is a critical value factor when evaluating pearls, particularly in the context of pearl strands or sets. Matching refers to the consistency and uniformity of various attributes among multiple pearls within a grouping. Several factors contribute to the matching value factor:

Size: Pearls in a set or strand should have a consistent size or a gradual and intentional progression in size, depending on the design.

Shape: Matching pearls often share a similar shape, whether round, near-round, oval, or another shape, to create a harmonious appearance.

Colour: Uniformity in colour is crucial for a cohesive and visually appealing look. This includes bodycolor as well as overtone in the case of pearls with additional hues.

Lustre: Pearls within a set should exhibit a similar level of lustre, ensuring a balanced and harmonious sheen across all pearls.

Surface quality: Consistency in surface quality, with minimal blemishes and imperfections, enhances the overall appearance of matched pearls.

The meticulous selection and arrangement of pearls based on these factors contribute to the overall aesthetic appeal and value of the jewellery piece.