Avoid exposing fine jewelry to extreme temperature changes, such as might be encountered by putting jewelry in a refrigerator or in-the-ground safe during the winter, where temperatures may be quite cold, then removing it and wearing it in a heated room. This is especially true with opals.
Store your jewelry in a dry place. Avoid extremes of temperature and humidity. Keep gemstone-studded jewelry, pearls, and gold jewelry separated from each other to prevent scratching. Store silver separately from gold jewelry, to avoid tarnishing the gold. Do not store pearls or opals for long periods of time in a safe deposit box. The dry, close air and dark environment seems to discolor pearls and dry out both pearls and opals. Keep fine jewelry in soft pouches or wrapped in soft cloth to help protect it. Don’t overcrowd your jewelry box. This can result in misplacing or losing pieces that might fall unnoticed from the case, or damage, such as bending a fragile piece or chipping a fragile stone.
Diamonds can scratch other gemstones very easily, and can also scratch each other. Ideally, to prevent scratching, diamond jewelry should be placed in a case that has dividers or separated compartments, or each piece should be individually wrapped (but not in facial tissue).
Pearls of all kinds (natural, cultured, South Sea, Tahitian, freshwater) are very soft, only 2 to 4 on the Mohs hardness scale. Because normal dust contains much harder quartz particles, pearls can be easily scratched if left uncovered. Store pearls in a separate pouch, preferably one lined with a soft fabric such as satin, or wrap it to prevent scratching the pearl’s surface on sharp metal edges or prongs, or against harder stones. Never toss carelessly into a purse or travel case. Avoid contact with ammonia, inks, hair spray, perfumes, cosmetics, and especially vinegar, which will immediately begin eating the pearl’s surface. These substances will spot the pearls, and some of the substances may weaken the string, making it susceptible to breakage.
Restring pearls periodically. If they are worn frequently, once a year is recommended. Fine pearls should always be strung with knots tied in the space separating each pearl to prevent them from rubbing against each other (which can damage the nacre), or from scattering and getting lost if the string should break. Treat any organic gem, such as amber, coral or jet as you would pearls.