I found this stone on the way. It looks as same as in the attached photo. Some say it's quartz crystal and some say it's something else. Can anyone help me out?
Judging by the appearance it could be either quartz or calcite. Try scratching it with a steel nail or knife blade. If the rock is scratched it is likely calcite. If the steel nail/knife doesn't scratch the rock it is likely quartz. This is because quartz is a 7 on the Mohs hardness scale, calcite is a 3 on the Mohs hardness scale and a steel nail/knife is around a 6.