is a Magnesium Iron Silicate Fluoride Hydroxide with formula (Mg, Fe)2SiO4)2 - Mg(F, OH)2 and hardness of 6-6.5
It's colors range from yellow to brownish -red and can be confused with humite or clinohumite.The best material comes from Pakistan and Burma , the size range from 0.20 to 3 ct.,but stones over 1 ct, clean are quite rare.
This piece comes from Mahenge ,Tanzania and compared with other locations the color is of a deep yellow.Eye clean. Rare.
Size: 8.9x6.9x4.4 mm.