Is a Calcium Sodium Aluminum Silicate Carbonate Chloride Sulfate with formula Na4(Al, Si)12O24Cl to Ca4(Si, Al)12O24(CO3, SO4) and hardness of 6.
The most common colours is yellow, but also comes in violet and purple , much rarer. This stone here is from Tanzania and it shows tubular parallel inclusions similar to the well know Oregon sunstone.Rare.
Size: 14.5x10x3 mm.
Weight: 3.57 ct.