Gold

Assuredly gold is purified by being submitted to the fire and if it contain any alloy or imperfection, it will disappear. That is the reason why violent tests become the cause of the everlasting glory of the righteous and are conducive to the destruction and disappearance of the unrighteous.

‘Abdu’l-Bahá, Tablets of ‘Abdu’l-Bahá v3, p. 655

Be not grieved; tests lead to the development of holy souls and the ardor of the flame of fire causeth the pure gold to shine and the violence of winds is conducive to the growth and thriving of a firm and well rooted tree.

‘Abdu’l-Bahá, Tablets of ‘Abdu’l-Bahá v2, p. 297

Be thou not sad, neither be thou unhappy; although the divine tests are violent, yet are they conducive to the life of the soul and the heart. The more often the pure gold is thrown into the furnace of test, the greater will become its purity and brilliancy and it will acquire a new splendor and brightness. I hope that thou art thyself in such a position.

‘Abdu’l-Bahá, Tablets of ‘Abdu’l-Bahá v2, p. 302-303

It is certain that to their discerning taste, the proffered treasures of kings would not compare with a single drop of the waters of knowledge, and mountains of gold and silver could not outweigh the successful solution of a difficult problem. To them, the delights that lie outside their work are only toys for children, and the cumbersome load of unnecessary possessions is only good for the ignorant and base. Content, like the birds, they give thanks for a handful of seeds, and the song of their wisdom dazzles the minds of the world's most wise.

‘Abdu’l-Bahá, The Secret of Divine Civilization, p. 21-22

Likewise, the pure gold shineth radiantly in the fire of test.

‘Abdu’l-Bahá, Bahá’í World Faith, p. 371

Not until man is tried doth the pure gold distinctly separate from the dross. Torment is the fire of test wherein the pure gold shineth resplendently and the impurity is burned and blackened.

‘Abdu’l-Bahá, Selections from the Writings of ‘Abdu’l-Bahá, p. 120