What is the ruling of Islamic Law on wearing energy stones?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
There is no objection to a woman adorning herself with precious and semi-precious stones — such as ruby, carnelian, or the like — so long as these are stones that women customarily wear as adornment.
As for what are known as "energy stones," if they are used with the intention of seeking remedy and healing, then such matters are governed by experimentation and scientific study — which either establishes that they have a tangible effect or does not — and all of this operates by the permission and will of Allah, Glorified and Exalted. If studies or practical experience do establish that such stones carry a beneficial effect upon human health, then there is no objection to using them. They are, after all, part of Allah's creation, much like medicinal substances extracted from plants or derived from other created things — provided that the Muslim does not believe that the stone itself is the source of benefit or harm. It is nothing more than a means among the many means that Allah has placed in this world, and the reality of all affairs belongs to Allah alone. And Allah the Almighty knows best.
What is the ruling on fasting the six days of Shawwal?
Fasting the six days of Shawwal is Sunnah. The Prophet ﷺ said: "Whoever fasts Ramadan and then follows it with six days of Shawwal, it is as if they have fasted for a lifetime." [Narrated by Muslim]
This is because fasting one month of Ramadan is rewarded as fasting for ten months, and the six days are equivalent to sixty days, completing a full year of fasting.
A pious man proposed to me and my father was hesitant in this regard because he is black, am I sinful if I accepted his proposal?
If the suitor is pious, color isn`t a drawback. However, try talking to your father kindly, so that he approves of your marriage with contentment, and that is better for you.
Is it valid to perform the obligatory prayer while sitting?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
Standing (Al-Qiyam) while having the ability to do so is one of the pillars (Arkan) of the prayer; the obligatory (Faridah) prayer is not valid without it. However, whoever is unable to stand may pray sitting down. As for voluntary (Nafilah) prayers, it is permissible to pray them sitting even if one is able to stand, but the one sitting receives half the reward of the one who prays standing. And Allah the Exalted knows best.