The emergence of various minerals

It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) that he said: "Various kinds of mines will appear. One of them will be near the Hijaz, to which the worst of people will come; it will be called 'Fir'awn'. While they are working in it, gold will suddenly appear from it, and they will be delighted with working there, when suddenly it and all of them will be swallowed up by the earth."
This hadith has an authentic (sahih) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Sayyiduna Ubadah bin al-Samit (may Allah be pleased with him) that he heard the Messenger of Allah (peace and blessings be upon him) say: "Soon a time will come when a person's best wealth will be sheep grazing on the tops of the hills between Makkah and Madinah, eating the leaves of thorny shrubs and basham trees. Their owner will eat of their meat and drink of their milk, while in the great settlements of the Arabs, trials will be convulsing." He (peace and blessings be upon him) said this three times, then said: "By the One in whose Hand is my soul! That one of you should have three hundred sheep whose meat he eats and whose milk he drinks would be dearer to him than these pillars of yours made of gold and silver."
This hadith has an authentic (sahih) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Sayyiduna Hudhayfah (may Allah be pleased with him) that he said: "What will be your state when you separate from your religion just as a woman opens at her private part when giving birth?"

It is narrated from Sayyiduna Hudhayfah (may Allah be pleased with him) that he said: "What will be your state when you separate from your religion just as a woman opens at her private part, not preventing anyone who comes to her?" At this a man said: "May Allah disgrace the one who is incapable!" So Hudhayfah (may Allah be pleased with him) said: "Rather, you will be disgraced."
Both of these hadiths have authentic (sahih) chains of narration, but the two Shaykhs (Bukhari and Muslim) did not record them.

It is narrated from Ibn Abi Mulaykah (may Allah have mercy on him) that he said: One day I went early in the morning to Sayyiduna Ibn Abbas (may Allah be pleased with them both), and he said: "I could not sleep last night until morning." I asked: "Why?" He said: "People said that a comet has appeared, so I feared that the Smoke (a sign of the Hour) might have arrived."
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it in their books; however, it goes against the position of Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), according to whom the sign of the Smoke has already passed.