Rules advice regarding Loose Impediments.
Let me first remind you that a golfer is NOT entitled to a perfect lie. You have to play the ball as you find it unless a Rule of Golf applies.
What is a Loose Impediment? Any natural object (eg twigs, fallen leaves, stones, loose grass, dead insects etc).
What can you do? You can remove them. But be careful, if your ball moves you get a one shot penalty.
What restrictions are there? Nothing partly or fully embedded can be removed (eg small stones). Also anything growing cannot be bent, broken or moved (eg grass, weeds, branches etc).
The best way to remove loose stones are to flick them away with your finger – you will see even the Pro’s on TV do this, it ensures the stone was loose in the first place. Larger stones can be lifted. Restrictions apply to where you will stand as well as where the ball is. SO you must be careful – you are allowed to fairly place your feet. You must not scrape the ground with your feet if this will likely disturb an object that was embedded. If you remove a Loose Impediment incorrectly, there is a two shot penalty.
The following photos show a typical example:-
Photo A – as you find your ball.
Photo B – the Yellow marked stones are not embedded – they are clearly loose on the surface of the ground.
Photo C – shows examples of stones that cannot be moved – indicated in Red. There are others, but you should get the idea from the examples I have given.

Regards
Michele Miller

