"To date, the oldest evidence of pure zinc comes from Zawar, in Rajasthan, as early as the 9th century AD when a distillation process was employed to make pure zinc." So, zinc only existed as an alloy before that.
I wonder how they could make brass before. Anyway, maybe you should rewrite the description, this is anterior to the 13th century (and arsenic is not quite a metal either).
I found this: "Although forms of brass have been in use since prehistory, its true nature as a copper-zinc alloy was not understood until the post medieval period because the zinc vapor which reacted with copper to make brass was not recognized as a metal."
being a solid is not a requirement to be a metal. And what is "room temperature?" Depending on where your room is located you could see all of these metals in liquid form.
a solid material which is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity (e.g. iron, gold, silver, and aluminium, and alloys such as steel).
A metal doesn't have to be a certain state of matter, it just has to have those traits.
1. Mercury is a metal. Its actually the only known metal that stays liquid in the room temperature
2. Playing with words sounds funny but with all seriousness room temperature is an internationally recognized term and ranges roughly between 15 C and 25 C. Details are below;
Although it's not a well established historical fact (in the sense of ancient writings specifically talking about gold, tin and copper), it is believed that Antimony (Sb) was isolated in ancient times, and may have been formed into small ornaments. FYI
a solid material which is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity (e.g. iron, gold, silver, and aluminium, and alloys such as steel).
A metal doesn't have to be a certain state of matter, it just has to have those traits.
2. Playing with words sounds funny but with all seriousness room temperature is an internationally recognized term and ranges roughly between 15 C and 25 C. Details are below;
https://en.wikipedia.org/wiki/Room_temperature
Although Brass was used for centuries beforehand, Zinc itself wasn't discovered until the eighteenth century.