Regarding gemstones and ambergris perfume from the ocean, should we pay zakat for them?
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions, and all those who follow his footsteps until the Final day.
Minerals and ancient treasures mean gold and silver mined from the earth. Gold and silver are mined and cleaned from any impurities on them are named Ma’dan. Whereas gold and silver buried in the earth before the spread of Islam is named Rikaz.
Rikaz treasure is a treasure found in the earth that was left by the ignorant during the jahiliyyah times, regardless of whether they are gold, silver and others and its signs are known. If there are doubts as to whether the treasure is left by the jahiliyyah or other people, then the treasure is considered to be from the jahiliyyah.
Rikaz treasure is not conditioned to complete the nisab, while the remaining of the treasure after paying the zakat is owned by the land’s owner if it is inherited or he’s the one who mined the land. (See al-Fiqh ‘ala Mazahib al-Arba’ah by al-Jaziri, 1/556)
Nisab (duration) for Ma’dan and Rikaz
- Ma’dan: The nisab for Ma’dan is the nisab for gold and silver, however, it is not conditioned to be a whole year. Furthermore, the zakat is obligatory as soon as a person takes out the gold and silver mined out from the mine, then he must pay the zakat at a rate of 1/40 or 2.5% from the total that he mined.
- Rikaz: The nisab for Rikaz is the same as the nisab for gold and silver, and it is not conditioned to complete the duration of a year but it is obligatory to be paid immediately. The obligatory rate for the zakat is 1/5 or 20% from the total that he gained.
(See al-Fiqh ‘ala Mazahib al-Arba’ah by al-Jaziri, 1/556)
The Issue of Gemstones and Ambergris Fragrance
Abu Yusuf in his book al-Kharaj (pg.31) stated: Gemstones and ambergris obtained from the sea should be paid its 1/5 of zakat. The rate 1/5 is obligatory, for it is analogically deduced to rikaz treasure (treasure buried by the jahiliyyah in the earth), or because it is one of the two types of Allah SWTs creation that are contained in the earth. Hence, Allah SWT’s right to the treasures buried in the earth should be fulfilled. The basis of the issue for rikaz treasure is then made as the illat (same reason for qiyas) on the wealth taken from the sea.
The evidence presented by Ibn al-‘Arabi (in his opinion ambergris fragrance taken from the sea doesn’t need for zakat) follows the narration from Ibn Abbas, he said:
لَا زَكَاةَ فِي الْعَنْبَرِ ، إنَّمَا هُوَ شَيْءٌ يَقْذِفُهُ الْبَحْرُ
“Zakat isn’t imposed on ambergris fragrance. Ambergris is something excreted into the sea.”
Narrated by al-Baihaqi in al-Sunan al-Kubra (7843)  and Ma’rifah al-Sunan wa al-Athar (2506). Imam al-Bukhari also cited these words of Ibn Abbas in Bab Ma Yustakhraj min al-Bahr (Chapter: Anything excreted into the). (See Sahih al-Bukhari, 2/129) 
Moreover, ambergris is included in the benefits attained from the sea. Thus, there are no obligatory rights on it by analogically deducing it with fish.
This is the sahih understanding of fiqh, for the sea is not in the hands (owned) by the disbelievers that we can consider things taken in it as ghanimah wealth, however, it is included in the list of absolute permissible things the same with animals that we hunt.
If it is said: What is your opinion regarding gold from the sea? We answer: There is no narration regarding the ruling for this issue. There is a possibility that it is obligated for the gold to be imposed zakat because gold is not found in the sea. The existence of gold in the sea shows that it may be brought there by a flood. (See Ahkam al-Quran by Ibn al-‘Arabi, 3/338)
Some Hanafi scholars say: There is a possibility that things taken from the sea aren’t imposed with zakat, for in the oceans, there are hills of which none owns them.
 The narration is with the following wording: ‘لَيْسَ فِى الْعَنْبَرِ زَكَاةٌ إِنَّمَا هُوَ شَىْءٌ دَسَرَهُ الْبَحْرُ’
 The narration is with the following wording: ‘لَيْسَ العَنْبَرُ بِرِكَازٍ هُوَ شَيْءٌ دَسَرَهُ البَحْرُ’