New 6-7mm sea natural gray color pearl 18k gold with certificate

6-7mm sea natural gray color pearl 18k gold with certificate Five criteria for choosing pearls are as follows: 1. Size 2. Color (Body color, overtone, orient color) 3. Luster (Pearl surface shininess) 4. Shape (Round, oval, drop, button, or baroque) 5. Surface (The fewer defects, the better) This necklace meets the above high criteria. How to test if pearls are genuine? Tooth test method: Rub a pearl lightly along the biting edge of your upper front teeth. If it feels slightly rough, sandy or gritty, it's likely a cultured or natural pearl. This texture you feel is the layers of nacre that have formed over time. If the pearl feels smooth or glassy, it is likely an imitation.