Perchlor stone is found in "Russia" and "Canada" and has the following chemical and physical properties:

Physical properties

• The shape is octagonal
• The group oxides
  
• The scratch is light brown / yellowish brown
• Hardness 5.5 / 5
• The color is brown to black
• Translucent / Opaque
• The sparkle is glassy / resinous

Chemical properties

• Density 4.5
• Cubic crystal system
• The chemical formula is niobium oxide