Gemstones & Birthstones

Though Diamonds Direct is most notably a diamond manufacturer, we are proud to offer an extensive collection of fine precious and semi-precious gemstones. From loose stones to finished jewelry- we have a collection of colored stones that will exceed your expectations. Our skilled diamond experts are also extremely knowledgeable about colored gemstones and will help you choose the right colored gemstone jewelry to suit your budget and that special someone.

The most commonly requested precious gemstones are sapphire, ruby, and emerald. When determining the value and quality of a precious gemstone, color is the primary characteristic to take into consideration. Gemologists divide gemstone color into three categories: hue, tone and intensity.



  • February


  • March


  • April


  • May


  • June

    Pearl, Alexandrite

  • July


  • August


  • September


  • October

    Opal, Pink Tourmaline

  • November


  • December


  • Many gemstones have been chemically enhanced or treated to improve their color and appearance to the naked eye. Some of these treatments are permanent and undetectable, while others can be identified and may cause the color of the gem to change over time. Such enhancements must always be disclosed to the customer to ensure an informed buying decision can be made.

  • As an example of how a gemologist evaluates color, let’s study September’s birthstone- the sapphire. A sapphire can form naturally in all colors of the rainbow, except red. When a gemologist evaluates a blue sapphire, the color can vary anywhere between a pale watery gray-blue to deep greenish-blackish-blue.

    Sapphire can be extremely common and inexpensive, or rare and pricey- this is primarily determined by the color. The same can be said for emeralds and rubies alike.

  • The list of varying semiprecious stones is long and expansive and most customers are fond of birthstones like aquamarine, topaz, amethyst, and peridot. Refer to the birthstone chart above to help you select the perfect semiprecious stone for a birthday or important occasion.


A pearl is formed when a foreign object, such as a grain of sand, accidentally finds its way into an oyster or mollusk. In an effort to heal, the mollusk secrets a crystalline material called nacre which builds layers on the object lodged inside. After some period of time, the layers of nacre appear smooth, hard and luminescent- and a pearl is born!

Natural pearls, formed by the process identified above are very rare and very expensive because this process is based solely on chance. To accommodate the growing retail market, most pearls sold today are cultured pearls. Cultured pearls are made with the help of humans inserting an object into an oyster. The oyster is placed in to warm water while slightly open to help the pearl form over a period of several years. The process of creating cultured pearls began in japan in the late 19th century and has aided the industry in creating pearls of varying shape, color, size and quality in mass quantities.

Pearl Characteristics

  • Pearl quality can vary dramatically, and just like other gemstones, only a tiny percentage are beautiful enough for use in jewelry. Characteristics that contribute to the value of a pearl are luster and nacre thickness, surface, shape, color and size.


    Luster is an important factor in determining the value of a pearl. It is a combination of surface brilliance and glow. The thickness of the iridescent layers surrounding a pearl's nucleus dramatically affects a pearls luster. This combined with color and size is how a price is valued.


    Perfectly round pearls are the rarest and most valuable. Baroque pearls, which are asymmetrical in shape, can be lustrous and appealing, and often cost less than round pearls. A clean, smooth, blemish-free surface is also preferred and more valuable.


    Cultured pearls can be found in a wide variety of colors- shades from rose to black and everything in between may be created by the oyster or dyed by man. Whatever the color, it should appear to emanate from deep within the pearl.

  • SIZE

    Millimeter size is how cultured pearls are measured. They can be smaller than one millimeter, as in the case of tiny seed pearls, or as large as twenty millimeters for a big South Sea pearl. As with diamonds, size influences price.

Pearl Origins

  • In addition to quality, pearls are identified and labeled based on their origin:


    Cultured in China and Japan. Most known for their luster, akoya pearls are considered the classic pearl. They are generally white or cream colored with overtone colors of rose, silver or cream. Sizes range from 2 to 11 mm.


    Cultivated in mussels in lakes and rivers, these pearls grow in an awesome variety of colors and shapes. These pearls are very affordable.


    Cultured from the silver or white-lip oyster, primarily in the northern waters of Australia, Indonesia and the Philippines, these pearls grow to exceptional size; 10 to 20 mm. These are highly prized and precious.


    Cultured from the black-lip oyster in the waters of the South Pacific, these pearls come in larger sizes, from 10 to 20 mm, and a variation of colors including black, gray, burgundy, peacock and gold. Mystical and dark, the popularity of Tahitian pearls has surged in recent years, making strands of these pearls one of the most sought-after pieces of jewelry.