The Rose Medallion from 1840
Rose Medallion is the pattern with the widest variations in forms, pattern, and quality. Four alternating panels around a central gold circle ("medallion") enclosing a bird and a tree peony characterize it. Within the four panels are birds, flowers, butterflies, and people in a house. Separating the panels are scrollwork vines, and flying "Fu" bats, a symbol for good luck and happiness.
The oldest pieces of antique Rose Medallion china date back to around 1840. They will not have any words or Chinese characters on the bottom. Early porcelain also has more pitting, may have a gold rim, may have scratches from use and the artwork in general is better and more detailed.
Rose Medallion China made from 1890 to around 1915 will have the word "China" on the bottom. After 1915, the words "Made in China" can be found. If you find pieces that have "Made in Hong Kong" or Chinese lettering on the bottom, these pieces are not considered antique because they are too modern.
Large Rose Medallion china pieces dating back to the mid to late 1800's can be worth several thousand dollars. Common items like plates and cups that date back to the early 1900's and late 1800's are usually worth under $100. Most items from the early 1900's on are also valued under $100, however, there are always exceptions. The condition and appearance of the item always makes a difference in the value. 
Excellent condition for the age- may have very minor fading in some small places.  
Please see pictures and just ask if you would like to see more from a specific angle or of a certain area on the piece.