Skip to main content

Table 1 Classification of garnet on the basis of chemistry and inclusion/lamella phases

From: Hydrous Na-garnet from Garnet Ridge; products of mantle metasomatism underneath the Colorado Plateau

   Chemistry Exsolution lamella phases
Garnet group Color Prp (mol%) Alm (mol%) Grs (mol%) Cr2O3 (wt.%) Cpx Amp Ap Rt Ilm Ctn Sri Crm Cr-Spl
 A. Cr-rich pyrope Red-purple 67–74 13–18 7–11 1.0–6.4     + + + + + +
 B. Cr-poor pyrope               
  B1. Amp type Brown 49–66 18–28 16–26 <0.4   ++ + ++ ++ + +   
  B2. Ilm-only type R-brown 49–68 20–38 12–19 0.4–2.0      ++     +
  B3. Dense lamellae type Black 54–72 18–33 12–15 <1.0 ++ ++ + ++ ++   +   
  B4. Cpx-Amp type Light brown 61–76 13–27 6–11 <0.6 ++ +   ++ ++     
  Inclusions without lamella textures
Garnet group Ol Opx Cpx Ti-Chu Chl Spl Crn Dol Mgs Ap sulfides Multi   
 A. Cr-rich pyrope ++ ++ ++ + + +      + +a   
 B. Cr-poor pyrope               
  B1. Amp type    ++   +    + + + +    
  B2. Ilm-only type ++ ++ ++   +      + + ++b   
  B3. Dense lamellae type    ++    + +    + + ++c   
  B4. Cpx-Amp type + +          +    
  1. Ap apatite, Ctn crichtonite, Sri srilankite, Crn carmichaelite, Cr-Spl chromian spinel, Ti-Chu titanian clinohumite, Crn corundum, Dol dolomite, Mgs magnesite
  2. aMulti phase inclusions composed of Dol, Mgs, Amp, Phl, Rt, Ap, Cr-Spl, and sulfides
  3. bMulti phase inclusion composed of gas, liquid-H2O, and solid phases (rutile, chlorite, calcite, and barite)
  4. cMulti phase inclusion composed of Dol, Mgs, Amp, Cpx, Opx, Ab, Ap, Rt, Ilm, and sulfides