In my village this type of stone is quite easy to get because there is a river where to look for it. Although in the river there are many stones like this, you must be careful to get them because usually beautiful stones are covered with thick skin or look ordinary.
People who are proficient can definitely tell which stones have good potential and which are not in nature.
Usually to find out the contents of the stone we have to split it, if the content is good then then it is processed to make it more beautiful.
River stones like this have many names and types, the price also varies, depending on the quality and beauty