﻿Geology 
  and 
  Mineralogy. 
  431 
  

  

  mula 
  would 
  then 
  be 
  3 
  Si0 
  2 
  , 
  2R 
  2 
  3 
  or 
  of 
  a 
  niineral 
  quite 
  distinct 
  

   from 
  the 
  gadolinite 
  and 
  yttrialite 
  with 
  which 
  it 
  is 
  found 
  asso- 
  

   ciated. 
  For 
  this 
  silicate 
  so 
  remarkably 
  rich 
  in 
  yttria, 
  I 
  propose 
  

   the 
  name 
  of 
  Rowlandite, 
  after 
  Professor 
  Henry 
  A. 
  Rowland, 
  

   whose 
  spectrographs 
  work 
  on 
  the 
  so-called 
  " 
  rare-earths 
  " 
  is 
  so 
  

   novel 
  and 
  important. 
  As 
  opportunity 
  offers 
  a 
  more 
  extended 
  

   description 
  will 
  be 
  given 
  of 
  this 
  very 
  interesting 
  new 
  species. 
  

  

  4. 
  Anatase 
  from 
  the 
  Arvon 
  Slate 
  Quarries, 
  Buckingham 
  Co., 
  

   Va.; 
  by 
  George 
  H. 
  Williams 
  (communicated). 
  — 
  The 
  rarity 
  

   of 
  American 
  localities 
  for 
  anatase 
  is 
  a 
  sufficient 
  warrant 
  for 
  

   recording 
  a 
  recent 
  discovery 
  of 
  this 
  mineral 
  in 
  its 
  original 
  posi- 
  

   tion, 
  made 
  by 
  the 
  writer 
  during 
  June 
  last. 
  In 
  the 
  course 
  of 
  a 
  

   trip 
  through 
  central 
  Virginia 
  occasion 
  was 
  taken 
  to 
  visit 
  the 
  

   State 
  quarries 
  five 
  miles 
  south 
  of 
  Bremo 
  Bluffs 
  on 
  the 
  James 
  

   River 
  railroad 
  in 
  Buckingham 
  County. 
  The 
  largest 
  of 
  these 
  

   quarries, 
  belonging 
  to 
  the 
  Williams 
  Brothers, 
  is 
  situated 
  at 
  the 
  

   terminus 
  of 
  the 
  short 
  branch 
  railroad, 
  Arvon 
  station. 
  This 
  con- 
  

   tains 
  the 
  best 
  quality 
  of 
  slate, 
  but 
  it 
  is 
  proportionately 
  devoid 
  of 
  

   anything 
  of 
  mineralogicai 
  interest. 
  About 
  a 
  mile 
  west 
  of 
  this 
  

   place, 
  however, 
  where 
  the 
  slate 
  of 
  this 
  district 
  was 
  first 
  opened 
  

   in 
  what 
  is 
  now 
  known 
  as 
  the 
  Robert's 
  quarry, 
  the 
  cleavage 
  is 
  

   less 
  perfect 
  and 
  regular, 
  while 
  cross 
  joints 
  are 
  of 
  frequent 
  occur- 
  

   rence. 
  These 
  irregularities, 
  which 
  detract 
  so 
  seriously 
  from 
  the 
  

   economic 
  value 
  of 
  the 
  slate, 
  make 
  this 
  quarry 
  more 
  interesting 
  

   than 
  the 
  other 
  to 
  the 
  geologist 
  and 
  mineralogist. 
  Here 
  beauti- 
  

   fully 
  crinkled 
  varieties 
  of 
  slate 
  occur, 
  and 
  one 
  regularly 
  mottled 
  

   sort 
  is 
  quite 
  abundant, 
  which 
  in 
  the 
  field 
  was 
  surmised 
  to 
  contain 
  

   ottrelite, 
  but 
  was 
  found 
  on 
  more 
  careful 
  examination 
  to 
  owe 
  its 
  

   knots 
  ("knoten") 
  to 
  small 
  rhombohedrons 
  of 
  some 
  carbonate 
  

   which 
  is 
  but 
  feebly 
  transparent 
  on 
  account 
  of 
  the 
  great 
  number 
  

   of 
  inclusions, 
  probably 
  of 
  carbonaceous 
  matter, 
  which 
  it 
  con- 
  

   tains. 
  Huge 
  blocks 
  of 
  this 
  imperfect 
  or 
  " 
  bastard 
  slate 
  " 
  have 
  

   been 
  thrown 
  aside 
  as 
  worthless, 
  and 
  it 
  was 
  on 
  the 
  end 
  of 
  one 
  of 
  

   these, 
  cut 
  off 
  very 
  evenly 
  at 
  right 
  angles 
  to 
  the 
  cleavage 
  by 
  a 
  

   cross 
  joint, 
  that 
  the 
  anatase 
  crystals 
  were 
  found. 
  

  

  The 
  surface 
  presented 
  by 
  this 
  joint 
  plane 
  was 
  of 
  large 
  size 
  and 
  

   was 
  completely 
  covered 
  with 
  small 
  quartz 
  crystals, 
  among 
  which 
  

   were 
  scattered 
  minute 
  individuals 
  of 
  pyrite 
  and 
  the 
  anatase. 
  The 
  

   latter 
  was 
  fairly 
  abundant 
  and 
  closely 
  resembles 
  the 
  black, 
  

   metallic, 
  steep 
  pyramidal 
  variety, 
  so. 
  well 
  known 
  from 
  the 
  

   Tavetsch 
  valley 
  in 
  Switzerland. 
  Hardly 
  any 
  crystals 
  were 
  

   noticed 
  over 
  a 
  millimeter 
  in 
  length, 
  while 
  most 
  were 
  less 
  than 
  

   this. 
  No 
  forms 
  except 
  the 
  unit 
  pyramid, 
  1 
  (ill), 
  and 
  the 
  base, 
  

   (001), 
  were 
  observed. 
  The 
  pyramidal 
  faces 
  are 
  horizontally 
  

   striated 
  and 
  often 
  built 
  up 
  into 
  little 
  flights 
  of 
  steps 
  by 
  an 
  oscil- 
  

   latory 
  combination, 
  as 
  is 
  so 
  frequently 
  the 
  case 
  with 
  the 
  Swiss 
  

   crystals. 
  The 
  faces 
  have 
  a 
  high 
  metallic 
  luster 
  but 
  are 
  broken 
  

   by 
  growth, 
  irregularities, 
  and 
  vicinal 
  planes, 
  which 
  makes 
  the 
  

   reflected 
  images 
  multiple 
  and 
  the 
  measurements 
  unsatisfactory. 
  

   The 
  best 
  crystal 
  gave 
  : 
  

  

  