Hence the prohibited items are few and precisely defined, whereas the lawful ones are without limit or number.

5 – Khazz: This refers to a worm that excretes filaments and winds them around its body; once it has fully enclosed itself in this cocoon it dies, and the resulting fabric is the khazz silk that is forbidden for men.

In our times a man-made khazz has appeared that is identical in appearance to the natural variety. This synthetic material is not included in the prohibition, for a ruling of unlawfulness belongs solely to Allah and His Messenger, and whatever they have not declared unlawful remains permissible; the default in such matters is permissibility. Nevertheless, it is advisable to avoid wearing it for several reasons:
(a) Its resemblance to genuine silk may mislead the uninformed observer, who will then imitate the wearer, thereby opening a door to wrongdoing.
(b) Whoever grazes his flock near a protected pasture is liable to stray into it; imitation here may lead, step by step, to wearing real silk.
(c) It produces softness and effeminacy in men, whereas a man is expected to display firmness and masculinity.
(d) It may expose the wearer to backbiting and criticism from those who assume he is dressed in natural silk; steering clear of it is therefore safer and further removed from harm.

6 – Substances that are called “gold” but are not the red (i.e., actual) gold—such as platinum and diamonds—do not share gold’s ruling of prohibition.