Hindu lore has it that there are nine gems. For example shaiva tantra-s mention these as the material from which li~Nga-s are made:
mANikya-mukte tvatha vajra-nIlau vaiDUrya saMj~naM haritAshmanA cha |
tat puShyarAgaM sphaTikaM pravAlaM navaiva ratnAni bhavanty amUnI ||
mANikya: ruby; mukta: pearl; vajra: diamond; nIla: sapphire; vaIDUrya: beryl; haritAshmana (marakata): emerald; puShyarAga: topaz; sphaTika: quartz; pravAla: coral.
Some Indic words for gems have traveled far: Beryl comes from the Prakritic form of vaiDUrya (veruliya) and smaragdus (emerald) from a Dravidianized form of marakata via a Semitic intermediate. Other such lateral transfers into Middle Eastern languages are also a possibility. But what is the etymology of vaiDUrya itself ?
The main investigation in this regard is that of AK Biswas, who adduces several explanations for the origin the names of the beryl family of minerals. However, his arguments are to me not entirely supported, suggesting that the matter is not yet resolved.
Biswas posits that the Prakritic veruliya is a loan from Dravidian. He suggests that the Dravidian precursor was actually a place name like Belur or Velur, which were beryl processing centers. He suggests that pata~njali’s etymology that vaiDUrya comes from the place where it was cut supports the origin from Velur or Belur. While superficial this Dravidian theory sounds nice it actually has several problems on scrutiny.