Holiday engagement season sparks new ring cycle

Holiday engagement season is in full swing: indeed, December is the No. 1 month of the year to pop the question, according to Knot.com.

One big trend on the rise for engagement rings is customization -- like taking gems from a family heirloom and putting them in a new setting, à la Prince Harry's ring for Meghan Markle, which used two stones that belonged to his mother, Princess Diana. According to the Knot's annual engagement survey, 45 percent of respondents are planning to purchase engagement rings with a custom design.

Using a stone that's been passed down for generations but updating the ring with a modern design is one way couples are staying true to their roots. 

"We definitely see that, it's something really sentimental for either a bride or a groom, and people are always looking to their family to carry on a tradition," Knot.com Managing Editor Kristen Maxwell Cooper told CBS MoneyWatch.

Thinking of following suit? Here's a few things you should consider before updating a family jewel. 

Rock solid

"The first thing to do is to have your piece looked at -- bring it into a jeweler and have it assessed, make sure they are genuine gemstones or metals that can be reset. And then it is a matter of working with a jeweler who has experience in custom design." said Jennifer Gandia of Greenwich Street Jewelers.  

Another important consideration? The kind of stone you'll be using. Diamonds are still the most popular choice for engagement rings, and they are the hardest stone -- helpful if you are looking for something to wear every day happily ever after. In recent years, stones like sapphires and opals have become more popular for use in engagement rings, but opals are porous and are a softer stone that can be easily damaged.

"With a soft stone you may run into issues [they are more easily damaged] -- it's an issue with opals which are very popular right now. An opal is going to look very different after year ten," Gandia said.

Set a budget

"Engagement rings are a big expense -- the average couple spends more than $6,000 for a ring," Knot.com's Cooper said. But once people make a budget they tend to stick to it, she added: "The three month salary rule is going by the wayside. Couples are really thinking about what they feel comfortable spending and not feel pressured to spend money they don't have."

It's important to have the number you are ready to spend in mind before heading into a jewelry store -- as much to keep you within budget as to let the jeweler know how to proceed.

"There's nothing worse than falling in love with something that's two or three times more expensive than you wanted to spend," said Dana Walden Chin, who specialize in custom engagement rings and resetting gemstones. "We always coach our clients to have a budget range and set a ceiling. Once you do that, it allows the designer to show you options that hit both your aesthetic criteria and your budgetary constraints."

If you already have the stone, resetting a ring can be a bargain by comparison. At Chin's Manhattan-based shop, resetting a ring starts around $1,900 if you use one of the standard designs. Keep in mind that costs increase if you use a pricier metal, like platinum, or if you are adding additional details like side stones or other accents.

Finding a gem of a jeweler

Perhaps the biggest consideration is finding a jeweler who can carefully assess your stone and help you decide the best way to set it. "It is so important to find a jeweler who you love and has been part of the community and sit down and have that conversation. You want to find someone you trust," said Amanda Gizzi, a spokeswoman for the industry group Jewelers of America.

Lifestyle can be another factor to take into consideration: A doctor who needs to put gloves over a ring may want a lower-profile setting, rather than a high profile setting, which may be a hassle for everyday wear. "You might have it in your head you want a certain kind of setting, but if you live an active lifestyle you don't want it to get caught on things," Gizzi said.

Perhaps the most important thing to keep in mind: Are you ready to part with the old piece for the sake of the new?

"If you're talking about a stone that's in a piece of jewelry, one of the things that's really important is to wrap your head around the fact that that setting, that pair of earrings, that necklace may not be usable once you remove the stone from it...so getting ready is the first piece," Chin said.