Moss and tree agates are formed from chalcedony, though this stone lacks the characteristic banding that would make it a true agate. The green inclusions are iron or manganese, and often look like ferns or other kinds of vegetation.
According to The Crystal Bible by Judy Hall, moss agate is "a stabilizing stone strongly connected with nature" and is refreshing and a highly optimistic stone. We have a customer that swears by putting pieces of moss agate with her potted plants, and we find the stone to be very linked to the vitality of life.
It is not known when or where pendulum divination first developed. In the modern era, pendulums like this one are typically used by assigning an answer to a particular direction of swing or a type of movement, then asking it a question and awaiting it to take on the answering movement. Most typically this is done with a yes/no question, with "yes" being a lengthways movement, and "no" being a crossways movement, but some versions allow for multiple directions, while others may use circular movements. Some people prefer to use a pendulum mat, in which lines are drawn from the same connection point, and each assigned a possible meaning.
Pendulums are also used to measure time and to focus the mind in meditation.