When you start shopping for an engagement ring, always prioritize the cut, which plays the largest role in the diamond's beauty. A well-cut stone sparkles more and can even look bigger. It’s important to understand that antique diamonds were cut differently than they are today; while their faceting is not as brilliant as contemporary cuts, they are prized for their unique beauty and rarity.

The second most important factor is color. The GIA’s color scale rates diamonds in ranges, from D (colorless) to Z (light yellow). (Do not confuse yellowish diamonds that have a low color grade with fancy yellow diamonds, which have a different grading system.) Some cuts can disguise or reveal color; a round brilliant stone looks whiter than any other, while step-cut stones, such as emerald and Asscher cuts, will make a yellowish tint more obvious.

As for carat weight, the number isn’t everything. Because larger diamonds are rarer, their cost per carat is also higher. Diamonds are typically priced by tier, so a .98-carat diamond may be noticeably less expensive than a 1-carat stone — but the size difference will be imperceptible.

Another factor to stop obsessing over is clarity. The GIA’s 11 clarity grades range from “flawless” to “included.” But tiny imperfections that are only visible with magnification shouldn’t scare you away from an otherwise appealing stone.

Choosing a diamond engagement ring can be intimidating — there are so many technical details to understand. But it doesn’t have to be difficult. Here are some key things to keep in mind.

If you’re buying a new diamond, make sure it has a GIA report, which is the most accurate and respected assurance of the stone’s qualities. An antique diamond may not be accompanied by a GIA report, which is why it’s especially important to work with a trusted dealer.

That said, a GIA report doesn’t tell you everything. There are intangible qualities that contribute to a diamond’s beauty. It’s another reason you should work with a trusted expert and take your time to learn as much as you can.

When it comes to budget, forget the old “rule” about spending three months of salary on a diamond. It’s entirely possible to find an exceptional ring that lets you save up for equally important things for married life.

One way to save money on your diamond is to forget about the “colorless” range (D, E and F). A fancy cut (anything other than round brilliant) stone in the high “near colorless” range (G and H) is just as beautiful.

Here at 1stDibs, we have access to the world’s foremost jewelers and dealers, and they are always eager to share their knowledge in order to make you an expert, too. We’ve picked their brains and discovered some fascinating stuff. For instance, did you know that certain fancy cuts, including the ones lately loved by celebrities, are known to make a diamond look larger?

Another good-to-know, especially if you’re considering an antique ring: new diamonds are cut by machine and exhibit more brilliance, but vintage stones possess a unique romance and fire that only hand-cutting can reveal.

Do you already have a diamond or gemstone in the family that you never wear? We’re all for resetting family stones in custom-made jewelry, and we partner with jewelers who specialize in that. Even though we love the authenticity of old things, we also believe that you shouldn’t let sentimentality get in the way of appreciating them.

Ultimately, all the experts in the world can’t tell you what feels right. So explore beyond your boundaries and always keep an open mind — but trust your gut.

Unsurprisingly, engagement rings surged in popularity beginning in the Victorian era, a time of elaborate courtship rituals. Queen Victoria herself was an ardent jewelry lover and inspired the trends. Because this period spanned many decades (1837-1901) you’ll see a lot of variety, including sentimental motifs with colored gemstones; fanciful hammered gold designs; settings that combine silver and gold; rose-cut, old mine-cut and old European-cut diamonds; and the introduction of the prong-set solitaire diamond ring.

The Edwardian era was short (1901-1910) but marked a pivotal time for jewelry innovation. New technology enabled artisans to create delicate, lacy pieces from platinum, which had previously been too challenging to work with. Updated techniques also refined the old European-cut diamond. These advances are evident in the filigree, milgrain and garland-style designs of the period.

The Art Deco movement (1915-1930s) was defined by clean lines and geometric shapes expressed through luxurious craft. Square and rectangular diamonds in platinum settings created graphic shapes, sometimes contrasted with colored gemstones. These modern jewels renounced the ornate designs of previous eras for an artistic revolution inspired by travel, technology and women’s independence.

There’s nothing more timeless than a round brilliant diamond solitaire engagement ring, but there’s nothing more exciting than being different from everyone else. And choosing a unique style doesn’t have to mean you’re buying a fleeting trend without staying power.

The cluster ring, for instance, got its start in the Victorian era. When Kate Middleton received Princess Diana’s diamond-and-sapphire ring, it sparked a resurgence of interest in this style.

The ‘90s are back (already!), and that includes the halo ring, a center diamond with pavé diamonds surrounding its perimeter. Some even have a double halo — a compelling option if sparkle is your first priority, plus the frame of small diamonds makes the center stone look larger.

But why wear just one center stone when you can wear two? That, plus the romantic symbolism of a duo of diamonds (or other gemstones), is the appeal of the toi et moi ring. French for “you and me,” the style was popularized in 1796 when Napoléan, the future emperor of France, proposed to Joséphine.

Another multiple stone option is the eternity ring — a row of diamonds that wraps the finger with brilliance. Often worn as a wedding band, this style has also served as an engagement ring for women with extraordinary style and taste, including Marilyn Monroe and Audrey Hepburn.

Custom designed diamond engagement rings sound like something just for celebrities and the ultra-rich. But in fact, bespoke pieces can often cost less than a pre-made ring because you’re dealing directly with the maker.

Besides the potential for a friendlier price, a custom ring offers other perks. You can create a design with special meaning, use a stone from a family heirloom or simply make that impossible-to-find ring — the one that you have in your mind — come to life.

You don’t even need to meet with a jeweler in person. We’re all getting better at shopping and communicating remotely, which means that you have a world of jewelers to choose from. The process will likely include a discussion by phone, video chat and/or email, followed by a few rounds of ring renderings for your approval.

One caveat of custom-made: you’ll need some lead time before the proposal. Make sure you agree on a timeline with your jeweler.

Available in a rainbow of hues, colored diamond engagement rings are universally alluring but an actual option only for a select few — at least if you want the color of your stone to be gloriously intense, evenly distributed and vetted by a prestigious gemological laboratory.

The value of colored diamonds increases exponentially with the saturation of the color. Large, richly hued stones are exceptionally rare and so can fetch millions of dollars. Given what such a stone costs, the desire for a fancy-colored diamond must be deep and enduring. The gems are especially alluring for brides who want to express their individuality with a hue they love — whether pink, yellow, blue or even black — coupled with the fiery brilliance of a natural diamond.

The grading report accompanying your diamond, ideally from the Gemological Institute of America (GIA), is a great place to start. You might also want to consult the GIA’s guide to colored diamonds to better understand technical terms like “fancy light,” “fancy,” “fancy intense” and “fancy vivid.” These describe the intensity of a colored diamond’s color — the most important of the four Cs in determining its value.

If diamonds don’t seem right, what about a magnificent sapphire, ruby or emerald?

If you’re contemplating an engagement ring with a center stone other than a diamond, it’s probably because your sense of style leans toward the unexpected. Perhaps, too, you’re someone who adores color. While a white diamond can feel cool and sophisticated, colored gemstones are vibrant — bursting with warmth and character — and imbued with symbolic significance, transforming the ring into an eloquent, multilayered expression of love and commitment.

The design is simple and straightforward, yes, but eternity bands are not without nuance. Originating in the courts of 18th-century Europe, the style is distinguished by a single continuous row of diamonds. This endless circle of light symbolizes a love that’s infinite and everlasting, making it ideal for a wedding or for marking a milestone anniversary.

If using an eternity band as your engagement ring appeals to you, you’re in good company. There are a few celebrity brides who have given this approach lots of style credibility. Marilyn Monroe, for example, got a band from Joe DiMaggio that was made entirely with diamond baguettes.