Furthermore, natural mantle olivine usually contains TiChu as defects and patches (Kitamura et al. 2004), and the high field strength elements Nb and Ta (Scambelluri et al. Despite its accessory character, TiChu is thought to play an important role in the storage of water (McGetchin and Silver 1970), fluorine (Engi and Lindsley 1980), boron and lithium (Scambelluri et al.

2005), and kimberlite xenoliths (McGetchin and Silver 1970 Matsyuk and Langer 2004). TiChu is a common accessory mineral in hydrous ultrabasic rocks including antigorite serpentinite (Damour 1879 Brugnatelli 1904 De Quervain 1938 Bearth 1967 Möckel 1969 Trommsdorff and Evans 1980), metaperidotite from high-pressure metamorphic terrains (Möckel 1969 Evans and Trommsdorff 1983 López Sánchez-Vizcaíno et al. Clinohumite is the humite group mineral whose crystal structure is most closely related to olivine because it has the highest proportion of filled tetrahedral sites.

The generalized mineral formula of humite group minerals is where 0 < x < 0.5, M represents divalent cations (mostly Mg with minor Fe, Mn, and Ni), and n is one for norbergite, two for chondrodite, three for humite, and four for clinohumite. Titanian clinohumite (TiChu) is a member of the humite group minerals that constitute a polysomatic series with olivine (Thompson 1978 Veblen 1991, 1992).

No tichu meturemant