Pearls, June's birthstone is an organic gem, created when an oyster covers a foreign object with beautiful layers of nacre. Shopping for pearls involves paying attention to a few important elements. High quality pearl jewelleries should consists a few factors, for example, high luster, good surface quality as well as matching colour, shape and sizes.

Luster is defined as the shine and glow of the pearl and it is the most important factor when deciding the value of the pearl. The quality of pearls is judged by the orient, which is the soft iridescence caused by the refraction of light by the layers of nacre - the layers of calcium carbonate that make up the pearl.

The longer the pearl is left in the oyster, the thicker the nacre. The thicker the nacre, the more lustrous the pearl. Though there are exceptions to that rule, the amount of nacre determines the reflective quality of the pearl's surface. And luster is the most important factor determining the quality of a pearl. It is especially important that the surface be without blemish, because luster is more often seen on a smooth surface without ridges that deflect the light.

A good quality pearl should be bright and not dull.

Pearls are organic gems and natural. When a pearl is look closely, they tend to have flaws such as tiny spots, bumps, or wrinkles. Pearls with fewer or lesser surface markings are rare and valuable.

Pearl comes in various colours, ranging from silvery white, to pinkish, to black. The consistency of the colour affects the value of the pearl. In some cases, fashion trends as well as colour demands will also affect the price of the pearl.

Pearls comes in many shapes, depending on how they are formed within the mollusk. Pearls usually comes in round, perfectly round. Round pearls are rare, not to mention, pearls that are flawless is even rarer. For this matter, pearls that are round and flawless are valuable and expensive.

Pearl's size is the diameter of the pearl measured in milimeter. Round pearls are measured according to their diameter while oval-shaped pearls are measured by their length and width.

The size of the oyster greatly affects the size of the pearl it creates. The larger the mollusks the larger the pearl. It is very rare and valuable to find large pearls.

To culture a large pearl, a large nucleus needs to be implanted into the oyster that will increase the chance of the mollusk rejecting the nucleus or died before a pearl is developed. On the other hand, a large nucleus can also affect the formation of the pearl. It is more likely that a large, mature pearl have greater surface defects.

Pearl size does not indicate its quality. However, the pearl size does affect the price. The large the pearl, the more expensive it is.