GENERAL CARE INFORMATION
Don't swim (or shower) with your jewellery on. Chlorine, saltwater and natural hot springs are all bad for a large number of softer stones, in addition to being very bad for all silvers, gold and copper.
Never wear your jewellery while applying hairspray, perfume, sunscreen, hand lotion, etc. Wait until anything you have sprayed/applied has thoroughly dried/absorbed before wearing your jewellery.
Avoid piling up your jewellery when storing it - you may be mixing hard with soft stones - which may then be scratched.
You may ask why this is so important - many people leave their wedding bands on 100% of the time and there seems to be no damage, right? So I can do the same thing, right? Well, no. Assuming the wedding bands have diamonds, those are the hardest stone on the Mohs Hardness Scale and will withstand a lot compared to the precious and semiprecious stones we use in our jewellery.
Interesting fact: Most household dust contains quartz, which has a Mohs hardness of 7. That means simply using a cloth to wipe the dust off a "softer" stone may scratch it. It is much safer to rinse your stone jewellery in clear water (using regular dish soap, if needed for cleaning).
THE BEST WAY TO CLEAN YOUR JEWELRY
Clean your handmade jewellery by wiping with a soft cloth or washing with regular mild dish soap with warm (not hot) water
Rinse well to remove all residue
Thoroughly dry with a soft cloth
Be sure your jewellery is completely dry before storing, as humidity increases tarnishing for all silvers - even those marked as anti-tarnish or tarnish resistant
Counter to folk wisdom, do not use toothpaste to clean your jewellery. Be careful not to expose softer stones to household chemicals or excessive heat
Do not soak any of my stone jewellery (reasons below)
Do not use ultrasonic or steam cleaners for any of my stone jewellery
Many stones have natural inclusions, are porous, brittle, soft, etc. This means the stones may wear down, fracture or break in an ultrasonic or steam cleaner. Even "hard" precious gemstones such as emeralds must not be put in ultrasonic cleaners as they can fracture.
Please do not use ultrasonic or steam cleaners to clean handmade Jewelry.
WHY IS THERE TARNISH ON MY HANDMADE JEWELRY?
Please understand that ALL types of silver will eventually tarnish. Many people believe that Sterling Silver is fake if it tarnishes. That is not true - Sterling Silver can and will tarnish (remember cleaning your family's Sterling Silver silverware?). Some Sterling Silver jewellery is plated with a layer to help slow the growth of tarnish (usually rhodium). As that plating wears down over time, tarnish will form. Even highly tarnish resistant Argentium® Silver will tarnish over time.
Copper jewellery can also "tarnish" - that is the nice coppery brown patina that forms over time. Some people like that patina, others do not - it's a personal preference. Raw copper can also get green or turn your skin green at the contact point. Many people think that is an allergic reaction to copper, but it is not. It's simply the copper element reacting with the minerals on your skin or in the air. If copper is sealed, it will help preserve the colour of your piece - but eventually, all sealants will wear down and then the copper will form its patina (or, depending on your personal skin composition, perhaps you will get some green from that copper).
HARDNESS OF STONES - AND WHY IT MATTERS
When a stone is called "Hard"or "Soft" it is usually in reference to that stone's rating on the Mohs Hardness Scale. The Mohs Hardness score is a relative scale indicating a stone's resistance to scratching. A softer stone can be scratched by a harder stone. "Hard" stones are stones at the top half of the Mohs Hardness Scale. Diamonds top the scale at a score of 10. Other stones (both precious and semiprecious) are spread from the very hard score of 9 to the softest score of 1 (Talc).
People assume that means a harder stone can withstand much more than a relatively softer stone - don't assume that! For example - Emeralds are hard stones, rating 7.5-8 on the Mohs Scale. However, they have natural inclusions, which means they may fracture in ultrasonic cleaners or if hit just right.
Unlike "hard" stones, stones on the lower half (<5.5) of the Mohs Hardness Scale are softer and will scratch more easily. More care needs to be taken when cleaning, wearing and storing so the stones aren't ruined or scratched. Soft stones on the bottom half of the scale will typically build up micro scratches from normal living (remember how house dust has quartz with a hardness of 7 in it?). This is normal and won't detract from the beauty of your stones.
Since you won't don't know the exact peculiarities of every single stone, even if you do know it's "hard" on the Mohs scale, the safest thing is to treat all of your stones as if they are soft and delicate.
POROUS OR SOFT STONES
It's important to remember that the Mohs Hardness scale only tells you about scratching, it doesn't tell you other qualities, such as natural inclusions, how soft or porous a stone is, etc. This is why you should not soak your stone jewelry.
Stones such as Lava are obviously porous to the naked eye. But most stones do not look soft or porous to the eye, even if they are. For example, pearl, opal, turquoise, amber, coral and onyx are some examples of stones that look "solid" to our eyes, but are either soft and/or porous.
Soaking in water can damage these types of stone, as residues left behind once the water has been absorbed build up, leaving them dull and lacking their original shine - and sometimes the stone may eventually fracture. Even when gently cleaning as described above, if stones get wet, they should always be allowed to dry completely before being stored away.