“ஸ்வயம்பூ தைவிகம் சைவ திவ்ய மானுஷம் ஆர்ஷகம்,
ராக்ஷஸம் பானமேவோக்தம் ஷட்விதம் லிங்கமுச்யதே....”
As per Karanagamam, one of the Agama Sastras, the Shiva lingams are classified into six types depending on how they came into existence. They are –
Swayambhu lingams that are believed to have been self-manifested.
Daiviga lingams are those that are believed to have been installed and worshipped by Goddess Parvathy and other celestial Gods (Devas). They continue to exist in the present day and on earth, but their origin is traditionally ascribed to the Gods.
Manusha lingams are those that have been installed by human patrons (rulers, chieftains, wealthy people etc.) in historical times.
Arshaga lingams are those that are believed to have been installed and worshipped by sages of yore (like Agasthiyar).
Rakshasa lingams are those that are believed to have been installed and worshipped by Asuras and Daityas (demons or demi-gods who oppose the Devas). For example, lingam installed by Ravana.
Bana lingams are those lingams that are found on the banks of rivers.
The term “Bana” has two meanings – it refers to water and to the demon (Asura) named Bana. It is believed that the demon Bana had worshipped millions of small lingams and had dropped them in several rivers like Ganges, Gandaki, Gomukhi, etc. These lingams can still be found on the banks of the rivers.
There is also reckoning of the relative merits of these lingams. The lingams of the Swayambhu, Daiviga and Arshaga types are considered to be the best (uttama) and rest of the varieties are of middling quality (madhyama).