I.
A lichen is a colony of organisms in which microscopic green algae or cyanobacteria live symbiotically among filaments of multiple fungus species. The relationship between them is cooperative in the sense that the algae produce food through photosynthesis whilst the fungus absorbs water and salts. Thus both of them have what they need of nourishment. The lichen takes the external shape of the partner fungus, hence the lichen is named after the type of fungus in question. The fungus is usually the main component of the mass of the lichen, but in some cases the mass is threadlike or gelatinous, but this rule is not applicable in all cases.
The colour of the lichen varies according to the type of algae; it may be green, brown or red.
Lichens have been used as a source for dyes since antiquity, because they contain extraordinary chemical compounds.
Lichens have also been used in the production of medicines and perfumes, and some are used as a source of nourishment.
See: Al-Mawsu`at al-`Arabiyyah (al-Ashin).
And Wikipedia (Lichen).
II.
The basic principle is that things are permissible unless they are proven harmful. Based on the scientific description of lichens, there are no shar`i reservations about consuming them, either on their own or mixed with other ingredients, or transformed into something else. The basic principle is that things are permissible unless there is evidence to disallow them or they turn out to be harmful.
Allah, may He be Exalted, says:
{He it is Who created for you all that is on earth} [Al-Baqarah 2:29]
{O mankind! Eat of that which is lawful and good on the earth} [Al-Baqarah 2:168]
{Say: Who has forbidden the decent apparel and goodly provision that Allah has bestowed upon His slaves?} [Al-A`raf 7:32].
It was narrated from Abud-Darda’ (may Allah be pleased with him), from the Prophet (blessings and peace of Allah be upon him), that he said: “Whatever Allah has permitted in His Book is permissible, and whatever He has prohibited is prohibited, and whatever He said nothing about is a concession, so accept the concession from Allah, for Allah is not forgetful.” Then he recited this verse: {And never is your Lord forgetful } [Maryam 19:64].
Narrated by al-Bayhaqi in As-Sunan al-Kubra, 19724; classed as sound (hasan) by al-Albani in As-Silsilat as-Sahihah, 2256.
However, if something is proven to be harmful, it is not permissible to consume it, because the Prophet (blessings and peace of Allah be upon him) said: “There should be neither harm nor reciprocating harm.” Narrated by Ahmad, and Ibn Majah (2341); classed as authentic (sahih) by al-Albani in Sahih Ibn Majah.
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said: You should realise that in principle, all things that exist of different types and characters are permissible in general terms for humans, and that they are pure, and it is not prohibited to deal with them, handle them and touch them.
This is a very general statement that is of great benefit and it is a great blessing; the scholars refer to it regarding many situations with which people are faced.
There are ten proofs of that – which spring to mind from the teachings of Islam – and they are: the Book of Allah, the Sunnah of His Messenger, following the path of the believers which is referred to in the verse {O you who have believed, obey Allah and obey the Messenger and those in authority among you} [an-Nisa’ 4:45] and {Your ally is none but Allah and [therefore] His Messenger and those who have believed} [al-Ma’idah 5:55]; then analogy, reflection, rational thinking and deep understanding.
End quote from Majmu` al-Fatawa, 21/535.
With regard to gelatin, we have given a sufficient and detailed answer concerning it previously on our website. See question no. 219137.
And Allah knows best.
