My birthday month is January, so I think there is no better time to highlight those items that make great birthday gifts — jewels and gemstones.

When you shop for someone who's really special in your life (or your favorite antiques appraiser), here are some tips that will help you get the most for your money.

• When it comes to colored gemstones, color has the greatest impact on value. Generally, the most valuable colored gemstones are those with a medium to medium-dark tone. Nine times out of 10, pure gemstones, or those with no enhancements, hold a higher value than others.

• A gemstone's clarity is determined by its natural environment. For instance, emeralds almost always form in nature with inclusions that are visible to the naked eye and, conversely, aquamarines do not. While clarity relates to value, inclusions are like birthmarks on a gemstone — they show its individuality, not its flaws. Still, inclusions impact the look of a gemstone and its value.

• Carat weight is the standard unit of weight for most gemstones, and the per-carat price will increase as size increases.

• Birthstones hold special meaning and symbolism. Based on the zodiac, the original birthstone calendar was created by ancient people who believed gems possessed mystical powers. The stones were said to bestow good health, prosperity and protection. Gemstones were associated with the months of the year and later, in 1912, the American Association of Jewelers adopted a list of birthstones.

• The ruby (July's birthstone) is one of history's most popular gems and is known as the King of the Gems. From the Latin word "ruber," meaning red, the ruby is mentioned in the Bible as the gem representing one of the 12 tribes of Israel. It is a hard gemstone and comes from the mineral form corundum, related to the sapphire. Rubies rarely occur in sizes over a carat, so a large ruby always will come with a very high price tag.

• While sapphires come in almost every color of the rainbow (for example, we call red sapphires "rubies"), blue is the most common color associated with the gem. Sapphires, or "safir" stones, are hard, durable and may be faceted cut or carved as cabochons. Sapphire cabochons are best known as star or cat-eye sapphires. Sri Lanka and Myanmar are sources for high-quality sapphires.

• The May birthstone and the gemstone that highlights the 20th wedding anniversary is the emerald. Emeralds have adorned royalty throughout history and their rich green color has long been associated with gardens and rebirth. The first emeralds were mined in ancient Egypt, and today, Colombia is the world's main source for the fragile stone.

If you are buying an emerald, expect inclusions. It is believed that the famed Roman Emperor Nero used slices of emeralds laced in front of his eyes to view gladiator fights. So emeralds served as the first sunglasses, perhaps?

• A quartz variety, the amethyst is related to rock crystal, citrine and agate. It is best known for its early Greek association with the god of wine, Bacchus. Beautiful purple amethysts were worn by high-ranking members of both the clergy and royalty. Folklore dictates that the amethyst would convey strength and wit to those who wore it. Amethysts may fade, so avoid prolonged exposure to bright light.

• With a hardness of 7.0 on the Mohs hardness scale, garnets (January's birthstone) are found in many places around the globe including Kenya, Brazil, Madagascar, Germany, Russia and the United States. Deep red garnets, popular in the early 1900s, were named for the deep red pomegranate fruit. Garnets are diverse in color and form in red, orange, yellow and green.

• In the first century, Roman naturalist Pliny the Elder wrote that an opal (October's birthstone) demonstrates a wide spectrum of color. Most opals come from Australia and they are rarely faceted because they're relatively soft compared to other stones. Opals should not be exposed to heat and should not be cleaned with ultrasonic or steam cleaning. They have been known to crack under harsh conditions.

It is advised that jewelry collectors store each colorful gemstone piece of jewelry separately in a soft cloth or padded box to avoid damage, scratching, or wear. When it comes to gems, look for size, color and value.

A Ph.D. antiques appraiser, author, award-winning TV personality and TV talk show host, Dr. Lori presents antiques appraisal events. Visit www.drloriv.com; Facebook.com/DoctorLori; or call 888-431-1010.