As I have mentioned before in my other guide, I am an experienced jewelry salesperson. During my time working for a corporate jeweler I learned many care tips which I was required to pass on to my customers and will now pass them on to my readers.
Pearls: Always wipe pearls with a damp cloth. Never soak, scrub, steam clean, or put them in an ultrasonic cleaner. After wiping them with a damp cloth, you may put a hair dryer on a cool setting and gently blow cool air over them to keep the strands inbetween the pearls dry. Store them in a dark, room temperature place. Pearls take on the color of their backgrounds. Storing pearls in a darkly-lined box or bag will cause them to dull. Exposure to light, especially display lights will cause them to dull.
Emeralds, Sapphires, and Rubies that are natural: Wipe with a damp cloth, never soak, steam clean or put in an ultrasonic cleaner. These stones naturally have inclusions that anything other than hand-cleaning can cause them to become enlarged or cause the stone to break. Especially take care with emeralds as they are usually treated with oils and dies which fill the cracks. You do not want to remove these protections by scrubbing or soaking the stones. Created counterparts of these stones are usually ok to soak, steam, or ultrasonic clean.
Quartz, Citrine, and Amethyst: Never ultrasonic clean, or expose to extreme light or temperatures. This will cause ugly, blotchy color changes.
More to come....
Professional Cleaning: Most corporate jewelers such as Zales, Shaws, and Kays offer professional cleaning services for free on items that they sell (actually, its usually in the terms of the service agreements that they sell to you or that come with the pieces automatically-check your receipt, they don't always tell you about it verbally). As an act of customer service they OUGHT to also clean your jewelry that they did not sell to you. Do this within reason. Do not bring in your entire jewelry box as this tends to be rude and takes time away from buying customers (not to mention, should they damage a peice that you did not purchase from them during a free cleaning they are not likely to replace it for you). If they have to have a professional jeweler remove the stones to get a thorough clean, it is normal that they charge you for this.
More to come...