374 A TREATISE ON METAMORPHISM. 



Table B. — Alteration products of minerals — Continued. 



Natrolite alters to prehnite. 



Nephelite alters to albite (conjectural), analcite, diaspore, gibbsite, hydro- 



muscovite (pinite), hydronepbelite, kaolin, musco- 

 vite, natrolite, sodalite, thomsonite. 



Noselite alters to calcite, chabazite, diaspore, gibbsite, natrolite, stilbite. 



Octahedrite alters to .rutile. 



Olivine alters to actinolite, antbophyllite, breunnerite, cbromite, hema- 

 tite, hercynite, hydrotalcite, liraonite, magnesite, mag- 

 netite, opal, quartz, serpentine, siderite, spinel, tremo- 

 lite. 



Opal alters to chalcedony, chert, quartz. 



Orthoclase alters to allophane, biotite, cimolite, damourite, epidote, gibbsite, 



halloysite, kaolin, muscovite, newtonite, pyrophyl- 

 lite, quartz. 



Parankerite alters to actinolite, calcite, dolomite, hematite, limonite, magne- 

 tite, sahlite. 



Perovskite alters to ilmenite. 



Phlogopite alters to chlorite, diaspore, gibbsite, hydrophlogopite, talc. 



Phlogopite (with biotite) alters to clinochlore, penninite. 



Plagioclases alter to analcite, chabazite, epidote, epistilbite, gibbsite, gis- 



mondite, heulandite, kaolin, laumontite, mesolite, 

 natrolite, paragonite, phillipsite, prehnite, quartz, 

 scapolites, scolecite, stilbite, thomsonite, zoisite. 



Prehnite alters to chlorite, quartz. 



Pyrite alters to hematite, limonite, magnetite. 



Pyrope alters to amesite, chlorite, enstatite, gibbsite, magnesite, quartz, 



serpentine, spinel, talc. 



Pyrrhotite alters to limonite magnetite, pyrite. 



Rutile alters to - hematite, ilmenite, titanite. 



Sahlite alters to actinolite, bastite, calcite, chalcedony, magnetite, quartz, 



serpentine, talc. 



Scapolite alters to biotite, calcite, diaspore, epidote, gibbsite, hydro- 



muscovite (pinite), kaolin, muscovite, quartz, talc. 



Scolecite alters to prehnite. 



Serpentine alters to brucite, hematite, limonite, magnesite, opal, quartz, 



webskyite. 



Siderite alters to griinerite, hematite, limonite, magnetite. 



Sillimanite alters to. . cyanite, kaolin, gibbsite, muscovite (damourite), talc. 



Sodalite alters to albite ( conjectural), analcite, diaspore, gibbsite, hydro- 



muscovite (pinite), hydronephelite, kaolin, musco- 

 vite, natrolite, nephelite (conjectural), thomsonite. 



Spinel alters to mica, serpentine, talc. 



Spodumene alters to albite, beta-spodumene, cymatolite, eucryphtite, micro- 



cline, muscovite. 



Staurolite alters to chlorite, gibbsite, magnetite, muscovite (damourite), talc. 



Stilbite alters to - albite, orthoclase. 



Titanite alters to - calcite, octahedrite, perovskite, quartz, rutile. 



Topaz alters to gibbsite, kaolin, muscovite, talc (steatite). 



Tourmaline alters to. biotite, chlorite, gibbsite, mica, steatite. 



Tremolite alters to calcite, talc. 



Vesuvianite alters to chlorites, garnets, micas. 



Zircon alters to hydrous zircon (malacon). 



Zoisite alters to calcite, gibbsite, kaolin, quartz. 



