Like the appearance of silver ...

Like the appearance of silver in mother of pearl, the world seems real until the Self, the underlying reality, is realized.
 Adi Shankara

Quotes from the same author

There is sorrow in finitude. The Self is beyond time, space and objects. It is infinite and hence of the nature of absolute happiness.
 Adi Shankara
As gold purified in a furnace loses its impurities and achieves its own true nature, the mind gets rid of the impurities of the attributes of delusion, attachment and purity through meditation and attains Reality.
 Adi Shankara
Thus one should know oneself to be of the nature of Existence-Consciousness-Bliss[Sat-Chit-Ananda].
 Adi Shankara
Each thing tends to move towards its own nature. I always desire happiness which is my true nature. My nature is never a burden to me. Happiness is never a burden to me, whilst sorrow is.
 Adi Shankara
Who but the Atman is capable of removing the bonds of ignorance, passion and self-interested action?
 Adi Shankara