Pectolite and Serandite - University of Colorado Boulder

Pectolite and Serandite - University of Colorado Boulder

Pectolite and Serandite Pectolite Serandite NaCa2Si3O8(OH) NaMn2Si3O8(OH) Information on hydrous pyroxenoids Composition Colors Hardness

Cleavage Pectolite NaCa2Si3O8(OH) White, colorless 5 {001} {100} Serandite NaMn2Si3O8(OH) Pink, brown 5 {001} {100} Environment: Secondary, alteration mineral in alkali-rich rocks,

associated with Zeolites. Famous localities: Patterson, NJ (pectolite); Mont Saint-Hiliare, Quebec (serandite) Crystallographic data for serandite and pectolite Space group a () b () c () V (3) (g/cm3)

Serandite Pectolite P-1 7.7185 6.9064 6.7624 350.56 90.492 94.085 102.775 3.431 P-1

7.0278 7.0236 383.29 90.524 95.181 102.524 2.880 from Jacobsen (1998) Hydrous Pyroxenoid structure (Pectolite) Yellow/orange - Ca (Mn) Green - Na

Light blue - Si Dark blue - H Hydrous pyroxenoid structure: T-O layers Yellow/orange - Ca (Mn) Green - Na Light blue - Si Dark blue - H Si-OH bonding in pectolite-serandite Takuchi and Kudoh (1977) proposed a split-mode bonding environment for H in pectolite, so that H would be bonded sometimes to O3 and sometimes to O4. However, this proposal could not be confirmed by later studies of serandite structure (Jacobsen 1998).

Polyhedral volumes in serandite M1 octahedra 14.806 3 M2 octahedra 14.356 3 Na polyhedra 25.418 3 Jacobsen (1998)

Cation ordering in serandite-pectolite Ca Site occupancy M1 ideal M2 ideal Mn NaMn2Si3O8(OH) Bulk composition

NaCa2Si3O8(OH) Na and Ca have preferred sites in the structure. Na will always occupy an M1 site if one is available; Ca will occupy an M2 site. Ohashi & Finger (1978) Comparison of pectolite-serandite with other 3repeat pyroxenoids Underbonding of oxygens allows hydrogen in the structure Apical oxygens are linked to the octahedra differently, causing the octahedra to distort differently with tetrahedral tilting Pectolite Wollastonite

Reasons to study hydrous pyroxenoids Insight into: Mechanisms of storing water in mantle rocks How H in minerals affects the minerals properties The unusual Si-OH bonding environment

Recently Viewed Presentations

  • When Chronic Pain Comes Knocking Kenneth R. Goldschneider,

    When Chronic Pain Comes Knocking Kenneth R. Goldschneider,

    The foot is cyanotic, a bit puffy, and she won't let you near it. Straight-A student, good family. PMHx (-); Meds (-); NKA; FHx (-) CRPS Type I Formerly: Reflex Sympathetic Dystrophy Algodystrophy Algoneurodystrophy Sudek's Atrophy Reflex Neurovascular Dystrophy Osteodystrophy...
  • Go To DreamSpark.com Upper Left Click On Students

    Go To DreamSpark.com Upper Left Click On Students

    Mapping Is *Optional* (see notes) At this point: If you registered with an email address that *isn't* a Microsoft Account (or, if your Microsoft Store account is tied to a different email address) you can link them here.
  • History of Aquaculture 1 Objectives 1. To describe

    History of Aquaculture 1 Objectives 1. To describe

    Is considered the "Golden Age" of common carp culture. ... - the application of engineering principles and techniques to problems in medicine and biology. United States Aquaculture in the 1990's. Production doubles from 1984 - 1994.
  • Pose, Pause, Pounce, Bounce

    Pose, Pause, Pounce, Bounce

    PPPB (Pose, Pause, Pounce, Bounce) is a simple, yet sophisticated, AfL (Assessment for Learning) questioning technique to help teachers move from good-to-outstanding. It also helps address differentiation in the classroom and encourages teachers to slow down, take risks and tease...
  • iTechnology and Communicative Drawing for Individuals with ...

    iTechnology and Communicative Drawing for Individuals with ...

    Color Choices This criterion was utilized given that color enhancement for communicative drawing purpose can be a valuable feature, for example, in distinguishing drawing of similar shape/features, but unique color representation (e.g., apple vs. orange).
  • What's new in C++ in vNext

    What's new in C++ in vNext

    What we'll talk about today. The C++ Renaissance is real and it includes you. There are some interesting trends driving the Renaissance. Visual C++ in Dev11 will help you capitalize on these trends
  • COLLABORATIVE STAGING FOR COLON CASES Nicole Catlett, CTR

    COLLABORATIVE STAGING FOR COLON CASES Nicole Catlett, CTR

    You have a CT scan showing a 8.4 cm lesion located in the cecum with stranding seen in the mesenteric tissue. The patient underwent a colonoscopy that showed adenocarcinoma. A colon resection was performed showing the cancer extended through the....
  • ECG LEADS - Eastern Illinois University

    ECG LEADS - Eastern Illinois University

    ECG LEADS Chapter 3 introduction The heart produces electrical currents The body acts as a conductor of electricity introduction An ECG is a recording of the electrical activity of the heart Different "views" of the heart can be recorded using...