The Formi education hub
Buying jewelry should not feel like an exam. These guides exist so you can walk into a purchase — or a consultation with our in-house jewelers — already knowing the words, the trade-offs, and the questions worth asking.
Diamonds
Natural versus lab-grownWhat's actually different (and what isn't)The shape guideRound, oval, emerald, cushion, and seven moreThe four CsCut, color, clarity, carat, in order of importanceCertificationGIA, IGI, EGL, and what each lab is really sayingBest stones for engagement ringsIncluding the colored alternatives
Gemstones
SapphireThe most worn colored stone in the worldRubyPigeon's blood and why origin mattersEmeraldThe most coveted green and the highest-maintenancePearlAkoya, freshwater, Tahitian, South SeaAlexandriteEmerald by day, ruby by nightOpalThe stone with every colorTopazSwiss blue, London blue, and imperial peachTourmalineEvery color and sometimes two in one stoneTanzaniteSingle-source, vanishing supplySpinelThe stone that fooled the British CrownMoissaniteHarder than sapphire, more fire than diamondMorganiteThe pink-peach beryl named for J.P. MorganPeridotGem-quality olivine in the one color it allowsCitrineYellow quartz, mostly heated amethystSunstoneFeldspar with trapped sunlightZirconThe natural gemstone, not cubic zirconiaIoliteThe dichroic “water sapphire” — violet-blue from one angle
Birthstones & anniversaries
Birthstone chartJanuary through December at a glanceJanuaryGarnetA family of stones — almandine, rhodolite, tsavorite, and moreFebruaryAmethystThe royal violet quartz, once rarer than rubyMarchAquamarinePale-blue beryl, the color of clear shallow seawaterAprilDiamondThe only single-stone birth monthMayEmeraldThe most coveted green gemstoneJunePearl, moonstone, alexandriteThe only month with three accepted stonesJulyRubyThe red corundum, also the 40th anniversary giftAugustPeridot, spinel, sardonyxThree modern options, each suiting a different styleSeptemberSapphireThe everyday luxury gemstoneOctoberOpal and tourmalineSoft and dramatic, or hard and colorfulNovemberTopaz and citrineThe two warm-toned November birthstonesDecemberTurquoise, tanzanite, zirconThree blue stones, three eras of the tradeAnniversary gifts by yearThe traditional and modern lists, year by year
Zodiac signs
The traditional gem for each astrological sign — older than the modern monthly birthstones, with a shortcut to shop the stones tied to your sign.
♈ Mar 21 – Apr 19Aries · DiamondThe ram’s fire pairs with the diamond’s unshakeable brilliance.♉ Apr 20 – May 20Taurus · EmeraldEarthy and enduring — emerald’s green is Taurus through and through.♊ May 21 – Jun 20Gemini · AlexandriteTwo-natured Gemini meets alexandrite, the stone that changes color.♋ Jun 21 – Jul 22Cancer · Ruby / MoonstoneRuby’s warmth and moonstone’s glow for the most nurturing sign.♌ Jul 23 – Aug 22Leo · PeridotBright, sunlit peridot for the boldest sign of the zodiac.♍ Aug 23 – Sep 22Virgo · SapphireSapphire’s clarity and discipline mirror Virgo’s exacting eye.♎ Sep 23 – Oct 22Libra · Opal / TourmalineOpal’s shifting balance of color for the sign of harmony.♏ Oct 23 – Nov 21Scorpio · Topaz / CitrineDeep, intense topaz and citrine for the most magnetic sign.♐ Nov 22 – Dec 21Sagittarius · Tanzanite / TopazTanzanite’s far-horizon blue for the traveler of the zodiac.♑ Dec 22 – Jan 19Capricorn · GarnetGarnet’s steady, grounded red for the most determined sign.♒ Jan 20 – Feb 18Aquarius · AmethystAmethyst’s visionary violet for the zodiac’s free thinker.♓ Feb 19 – Mar 20Pisces · AquamarineAquamarine’s sea-glass calm for the dreamiest sign.