This is a polished garnet stone, which is a group of silicate minerals that are often used as gemstones.
Garnets are most commonly known for their deep red color, though they can be found in a variety of colors including green, orange, and yellow. 
The name "garnet" is believed to have originated from the Latin word for pomegranate, due to the stone's resemblance to the fruit's seeds. 
Garnets are the birthstone for January and are said to symbolize love, protection, and friendship. 
The stone has a Mohs hardness rating of 6.5 to 7.5, making it a moderately hard gemstone suitable for everyday jewelry.