How Pearl and Alexandrite differ in what they are, color, hardness and care.
| Pearl | Alexandrite | |
|---|---|---|
| What it is | An organic gem formed inside a mollusk as layers of nacre build up around an irritant. Pearls are not mined or cut, and most are cultured with human help. | A rare variety of chrysoberyl that changes color with the light: "emerald by day, ruby by night". |
| Birthstone for | June | June |
| Colors | White; Cream; Pink; Peach; Lavender; Gold; Green; Blue; Gray; Purple; Black | Bluish green in daylight or fluorescent light; Purplish red in incandescent light or candlelight |
| Mohs hardness | 2.5 | 8.5 |
| Toughness | Usually good, but age, drying out and heavy bleaching can make pearls fragile. | Excellent, with no cleavage; suits rings and daily wear. |
| Everyday wear | Delicate | Great for everyday rings |
| Ultrasonic cleaner | Never | Usually safe |
| Main sources | Grown inside mollusks; most pearls sold today are cultured | Brazil, Sri Lanka, East Africa (natural stones are scarce; lab created stones are more common) |
| Common treatments | May be dyed, impregnated or coated; these treatments can change over time. | Usually untreated. Clean any fracture filled stones only with warm soapy water. |
Alexandrite is the harder of the two (8.5 on the Mohs scale). Both are June birthstones, so either makes a fitting gift. Choose by the color you love and how the piece will be worn; for a ring worn every day, the tougher stone will last better.
Sources: GIA: Pearl care and cleaning, AGS: Pearl, GIA: Alexandrite care and cleaning, AGS: Alexandrite. Checked October 16, 2026.
Birthstone of the month
On the first of each month: that month's birthstone, what it means and how to care for it.
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