Gold Filled Rings - When it comes to contact with water, gold filled can be treated like any gold pieces. Gold filled is not scratch resistant, therefore avoid any abrasives.
Blackened Rings - I personally wear my rings all the time and the color holds up well, the underside, which is closer to perspiration, will eventually lose its color, but the top should always keep its color. Do not wet the blackened pieces.
Gold Plated - In some of the larger pieces, I have used gold plating in order to keep the cost down ( the actual gold in the gold filled pieces, is 5% of the weight of the piece ). I tend to use gold plating in large pendants because they usually do not come in direct contact with skin that often ( perspiration and body chemistry can effect the plating ), therefore the chances of the plating coming off is minimal.
Pearls - Do not let any pearl jewlery come in contact with perfumes. When spraying perfume, be careful not to spray the pearl. Any pearl, even the most expensive, will be damaged by perfume. Try to put on your pearl jewelery after you have applied your perfume.
Store your jewelry in a well ventilated space. Avoid leaving in the bathroom because humidity is not good for most jewelery. When possible, your necklaces should be hung - this will also avoid them getting knotted.
Most of my rings are open at the bottom, so that the sizing can be adjusted, therefore be careful with them, especially in the winter, that they do not catch your knits - also, be careful with some of the pieces that are set with stones.