They are natural and untreated. They have lots of fire, but also have imperfections and defects. 

Approximately 3mm

They will come on a 925 sterling silver head pin. 

Opals are delicate gemstones. Avoid getting them wet. Store in an air tight bag out of the direct light. 

Use 24 gauge or thinner, soft wire with them. 

Please message me with any questions. 

Thank you! 

(BB22)