20 HINTS FOR OFFICERS IN THE DETECTION OF PRECIOUS STONES, 
Pyramidal, Dimetric, or Tetragonal System. 
Jacinth, Square prisms, ending in square pyramids, 
Jargoon, do do do do do do 
Epidote. Long oblique prisms, 
Apophyllite. 
Anatase. 
Rhombohedral, or Hexagonal System. 
Corundum gems. Hexagonal single and double pyramids. 
Emerald and Beryl. Hexagonal prisms. 
Tourmaline. Hexagonal prisms. 
Quartz. Hexagonal prisms. 
Phenakite. Hexagonal prisms. 
Prismatic, Trimetric, or Orthorhombic System. 
Chrysoberyl. Flat hexagonal crystals. 
Topaz. Right rhombic prisms. 
Peridot. Very rare in crystals. 
Tolite. 
Oblique, or Monoclinic System. 
Euclase. 
Spodumene. 
Hiddenite. 
Moonstone. 
Sphene. Wedge shaped pieces. 
“ Triclinic or Anathic” System. 
Axinite, 
TABLE V. 
COLOURS SHOWED BY DICHROISCOPE. 
Sapphire (blue). Greenish straw. Blue. 
Ruby (red). Arrora red. Carmine red. 
Tourmaline (xed). Salmon. Rose Pink. 
do (brownishred), Umber brown. Columbine red. 
do (brown). Orange brown. Greenish yellow. 
do (green). Pistachio green. Bluish green. 
do (blue). Greenish grey. Indigo blue. 
Emerald (green). Yellowish green. Bluish green. 
Topaz (sherry). Straw yellow. Rose pink. 
do (pink). Dull white. Rose pink. 
Peridot (pistachio). ~ Brown yellow. Sea green. 
Beryl (sea green). Straw white. Grey blue. 
do (pale blue). Sea green. Azure. 
Chrysoberyl (yellow): Golden brown. Greenish yellow. 
Tolite (lavender). Pale buff. Indigo blue. 
Amethyst (purple). Reddish purple. Bluish purple. 
Epidite (green). Emerald green. Yellow. 
Phenakite (yellow). White. Yellow or brown. 
