Everyday I learn more about the many ways in which various gemstones and precious metal finery might be damaged by improper care. Even something as subtle as too much sunlight may harm certain gemstones.
Attached here is another great resource with excellent information on caring for your fine jewelry. Some of it is common sense, but it is brief and very worth your while: https://www.gemselect.com/other-info/taking-care-of-gems.php
"Taking Care of Your Gemstones - A Simple Guide
Cleaning your gemstone jewelry doesn’t require any special accessories or appliances. A bowl of water with a few drops of dish detergent will do the trick. To clean behind the stone you can use a soft toothbrush but don’t scrub too hard as this could scratch the stone. Scrub gently and then rinse. Dry gently using a soft cloth.Always gently wipe off excess make-up and skin oils after wearing your jewelry. Use a nub free, 100% cotton cloth and gently wipe the piece clean.All organic gems should only be wiped clean with a soft cloth; pearl, coral, and amber are examples of organic gems.A home ultrasonic cleaner should be used with extreme caution and only by those who know how and which gems it can be used on. For example it can be used with ruby, sapphire and amethyst, however, it could damage gems such as emerald, turquoise, and pearl.Be very careful when using any soaking method to clean jewelry that has soft stones such as amber, lapis lazuli, or turquoise. Extended soaking in any solution may harm the polish of the stone.
Always store your gemstones separately to avoid scratches from harder gems. If possible, store each piece in a separate box. Soft stones like lapis lazuli, malachite, turquoise, amber and opal can easily be scratched by pin stems and the edges of other jewelry. Protect these gemstones by wrapping them in jeweler's tissue and storing them separately.
Sunlight and Heat
Make sure that gemstone jewelry is stored away from direct sunlight because a lot of gemstones, like amethyst, citrine and smoky quartz, can fade in sunlight. Opals also require extra special care. It is not advisable to put an opal ring on the window sill when washing your hands or the dishes, since strong sunlight can dry out the water in opal, which can cause hazing or color change. Heat should also always be avoided with regard to opal. Pearls should also be treated with particular care, since scratches, perfumes and household chemicals can wear away the nacre or cause color change quite easily. Emerald gemstones should also never be stored near heat.
When dressing, jewelry should always be the last item to be put on and the first to be removed. This is to avoid jewelry coming into contact with perfume or hairspray. Perfume and suchlike should always be sprayed on before wearing jewelry.
Wearing jewelry whilst swimming should always be avoided. The chlorine in the water can damage jewelry. Always remove rings and fine jewelry before using any product that contains bleach. Bleach can also cause gold and other metal alloys to deteriorate, leaving the metal irreparably damaged. It may sound obvious, but never use bleach to clean jewelry.
Besides chlorine, bleach, denatured alcohol, turpentine, acetone and ammonia can cause harm. These chemicals can dull or even pit the surface of softer gemstones. Petroleum-based products can actually melt amber if allowed to remain on the stone and they can do significant damage to pearls. These gemstones are soft and porous. Long-term exposure to chemicals such as hairspray, cosmetics, and perfume may damage such organic gemstones, especially pearls.
Never use toothpaste or other abrasives to clean metal or stones. There are countless websites that recommend toothpaste as a cleaner, but this is not a practice that is accepted by fine jewelers. Although the abrasives in toothpaste are great for your teeth, they can damage the surface of the metal, requiring the skill of a professional to buff and refinish it. Toothpaste will also scuff the surface of amber, lapis, turquoise and other gemstones, resulting in the fine polish which was produced by the skilled lapidary being permanently marred.