It is rare that our mind can be peaceful and let go of everything, but if we are able to achieve that state of mind just once, it is very precious, more precious than the ever busy thinking mind.
It is very easy to find pebbles or stones but they have little value. They may be found all over the mountain but they are not as valuable as just one diamond. If one manages to dig deep, a diamond may be found and will be more valuable than the whole mountain of pebbles.
The nature of the mind is the same. If we penetrate deep into peace and tranquility, free from thought for just one moment, the result is the same as finding a whole diamond.
The mind which sees the Dhamma is free from thoughts and turmoil, and is able to obtain Nirodha (the cessation of Suffering).