Lunar Rock Systematics

I. SEDIMENTARY (Regolith)

II. METAMORPHIC

 A. Shocked (monomict and polymict) rocks

 B. Impact (melt) breccias and glasses

III. IGNEOUS

 A. Mare-type

   1. Crystalline

     a. Ti-poor basalt (<1.5 wt% TiO2) [formerly VLT]

     b. Medium Ti basalt (1.5–6 wt% TiO2) [formerly low-Ti]

     c. Ti-rich basalt (>6 wt% TiO2) [formerly high-Ti]

   2. Glassy

     a. Green

     b. Yellow

     c. Orange

     d. Red

     e. Black

 B. Highland-type

   1. Coarse-grained (>3 mm) [and transitional types]

     a. Anorthosite

     b. Norite

     c. Gabbro

     d. Troctolite

     e. Dunite

   2. Fine-grained (<3 mm)

     a. Felsite

     b. KREEP basalt

   3. Fragmental (see II. above if metamorphic)