Hurricane_Mtn.

Hurricane Mtn., Conway, NH, Mineral Gallery Return to mindatnh front page. Click on image for larger view
This page is an alphabetical photo gallery of minerals from the Hurricane Mtn. Locality, New Hampshire. (A locality specific photo set from mindatnh.org) 14 species, 60 mineral photos, 13 mineral analyses, 2 site photos. A 2023 investigation of the Hurricane arfvedsonite and riebeckite failed in attempts with EDS and PXRD to differeniate these two species. (see Hurricane amphiboles study ) This web page continues with the historical definition of Hurricane arfvedsonite and riebeckite.
Hurricane topo view Hurricane Mtn., Conway, NH	Species: Hurricane topo view Locality: Hurricane Mtn., Conway, NH Notes: The Hurricane Mtn. locale is located to the north of the high point of the Hurricane Mtn. Road that goes between North Conway and the Maine border.
Peter's Quarry Hurricane Mtn., Conway, NH	Species: Peter's Quarry Locality: Hurricane Mtn., Conway, NH Notes: Peter Samuelson collected many fine arfvedsonite specimens from this large prospect pit on Hurricane Mtn. A low resolution, scanned, photo.
ALBITE Hurricane Mtn., Conway, NH 7 mm field of view	Species: ALBITE NaAlSi₃O₈ Locality: Hurricane Mtn., Conway, NH Specimen Size: 7 mm field of view Field Collected: Leroy Grant Catalog No.: Notes: Riebeckite "hairs" and zircon bipyramids are also visible in the top right of this photo.
AEGIRINE Peter's Quarry, Hurricane Mtn., Conway, NH 1.3 cm splintery mass	Species: AEGIRINE NaFeSi₂O₆ Locality: Peter's Quarry, Hurricane Mtn., Conway, NH Specimen Size: 1.3 cm splintery mass Field Collected: Bob Wilken - 2021 Catalog No.: u2564 Notes: Aegirine confirmed by EDS analysis The chemistry imputed from this analysis is Na_0.95Fe_0.71Si₂O_3.6 , normalized for 2 Si. This is close to the desired Na:Fe ratio of 1:1.... much closer than for the amphibole arfvedsonite and riebeckite species reported from Hurricane.
AEGIRINE Peter's Quarry, Hurricane Mtn., Conway, NH 1.8 cm splintery mass	Species: AEGIRINE NaFeSi₂O₆ Locality: Peter's Quarry, Hurricane Mtn., Conway, NH Specimen Size: 1.8 cm splintery mass Field Collected: Bob Wilken - 2021 Catalog No.: A Bob Wilken specimen Notes:
AEGIRINE Hurricane Mtn., Conway, NH 2 cm vertical field of view AEGIRINE Hurricane Mtn., Conway, NH 10 mm vertical field of view	Species: AEGIRINE Locality: Hurricane Mtn., Conway, NH Specimen Size: 2 cm vertical field of view and 10 mm close-up view. Field Collected: Leroy Grant - 1970's Catalog No.: 2154 Notes: In 2022, Bob Wilken found and identified (EDS) aegirine at Hurricane Mtn. These were mostly micro green splinters in the cores of matrix embedded arfvedsonite crystals. Alerted to this association, I reviewed a small lot of Leroy Grant Hurricane specimens, (acquired 2018), that I had dismissed as typical, non-descript, embedded arfvedsonite. One miniature chunk had these aegerine crystals. These were not as green as Bob's find, perhaps due to greater weathering. Aegirine has been on New Hampshire species lists for decades, reported from Red Hill, Moultonborough, My Red Hill collecting efforts had failed to find an example, so Bob's discovery of the Hurricane Mtn. occurrence was most satisfying.
ARFVEDSONITE Huricane Mtn., Conway, NH 1.2 cm tall arfvedsonite crystal on microcline crystal matrix with zircons ARFVEDSONITE Huricane Mtn., Conway, NH 1.2 cm tall arfvedsonite crystal on microcline crystal matrix with zircons	Species: ARFVEDSONITE NaNa₂(Fe²⁺₄Fe³⁺)Si₈O₂₂(OH)₂ Locality: Huricane Mtn., Conway, NH Specimen Size: 1.2 cm tall arfvedsonite crystal on microcline crystal matrix with zircons. Field Collected: Roger Eastman Catalog No.: A Don Dallaire specimen and photo. Acquired 8/22.
ARFVEDSONITE Hurricane Mtn, Conway, NH 4.25 cm crystal	Species: ARFVEDSONITE Locality: Hurricane Mtn, Conway, NH Specimen Size: 4.25 cm crystal Field Collected: Peter Samuelson A former Bob Whitmore specimen. Catalog No.: 4013. A Don Dallaire specimen & photo. Notes:
ARFVEDSONITE Hurricane Mtn., Conway, NH 2.4 cm terminated arfvedsonite crystal	Species: ARFVEDSONITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 2.4 cm terminated arfvedsonite crystal Field Collected: Attributed to Ernie Schlichter - Peter Samuelson joint diggings Catalog No.: 1749 Notes:
ARFVEDSONITE Hurricane Mtn., Conway, NH 4.2 cm arfvedsonite crystal in matrix	Species: ARFVEDSONITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 4.2 cm arfvedsonite crystal in matrix Field Collected: Tom Mortimer Catalog No.: 842 Notes: A polished grain EDS analysis gave a result that was very low in sodium and high in iron for the species. A second EDS analysis of of this same grain by Al Falster of the MMGM lab (without quantification) also suggested a high Fe content. Al's analysis showed moderate substitution of Mn, Mg, Al, Ca, and Ti. The RUFF web site provides a complex empirical chemistry for the arfvedsonite species: (Na_0.61K_0.39)Na_2.00(Fe²⁺_2.40Mg_0.80Mn_0.75Ca_0.05)₄(Fe³⁺_0.60Al_0.25Mn_0.15)(Si_7.99Ti_0.01)₈O₂₂((OH)_0.67F_0.33)₂ indicating the substitution elements present in Al's analysis.
ARFVEDSONITE Hurricane Mtn., Conway, NH 2 mm crystal blade ARFVEDSONITE Hurricane Mtn., Conway, NH 2 mm crystal blade	Species: ARFVEDSONITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 2 mm crystal blade Field Collected: Leroy Grant - early 1970's Catalog No.: u2223 Notes: Top photo: blade crystal in vug, termination partially obscured. 70 stacked images with Nikon objective. Helicon Method C. Lower photo: 26 stacked images with B&L 5X objective - different orientation. Helicon Method C - a bit grainy.
ARFVEDSONITE Hurricane Mtn., Conway, NH 11 cm terminated arfvedsonite crystal	Species: ARFVEDSONITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 1 cm terminated arfvedsonite crystal Field Collected: A gift from M. Chandler to the Harvard Mineral Museum Catalog No.: Harvard Mineral Museum #119209 Notes: This is a very large terminated arfvedsonite for Hurricane Mtn. A Kevin Czaja photo.
Amphibole cleavage Hurricane Mtn., Conway, NH 2 cm arfvedsonite crystal in matrix	Species: Amphibole cleavage Locality: Hurricane Mtn., Conway, NH Specimen Size: 2 cm arfvedsonite crystal in matrix Field Collected: Leroy Grant, 1970's Catalog No.: Notes: Magnified end view of crystal shows the amphibole cleavage of 124 and 56 degrees.
ASTROPHYLLITE Hurricane Mtn., Conway, NH 4.2 cm crystal blade, no matrix /div>	Species: ASTROPHYLLITE (K,Na)₃(Fe,Mn)₇Ti₂Si₈O₂₄(O,OH)₇ Locality: Hurricane Mtn., Conway, NH Specimen Size: 4.2 cm crystal blade, no matrix Field Collected: From Vince Valade collection. A gift from Gordon Jackson Catalog No.: 1942 Notes:
ASTROPHYLLITE Hurricane Mtn., N. Conway, NH 3 mm crystal in quartz	Species: ASTROPHYLLITE Locality: Hurricane Mtn., N. Conway, NH Specimen Size: 3 mm crystal in quartz Field Collected: Tom Mortimer Catalog No.: u36 Notes:
ASTROPHYLLITE Hurricane Mtn., Conway, NH 9 mm vertical field of view	Species: ASTROPHYLLITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 9 mm vertical field of view Field Collected: Leroy Grant -1970's Catalog No.: u2371 Notes: Golden astrophyllite hairs in quartz crystal.
ASTROPHYLLITE Hurricane Mtn., Conway, NH 15 mm vertical of view	Species: ASTROPHYLLITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 15 mm vertical of view Field Collected: Leroy Grant -1970's Catalog No.: nc Notes: Golden astrophyllite hairs in quartz.
BASTNASITE-Ce Hurricane Mtn., Conway, NH 0.5 mm compound crystal group BASTNASITE-Ce Hurricane Mtn., Conway, NH 0.5 mm compound crystal group	Species: BASTNASITE-Ce (Ce,La)(CO₃)F Locality: Hurricane Mtn., Conway, NH Specimen Size: 0.5 mm compound crystal group, two views. Field Collected: Bob Wilken - 9/21 Catalog No.: A Bob Wilken specimen & photo. HUR-Bastnaesite02AA Notes: Bastnasite-Ce confirmed by EDS analysis . Top photo taken with Nikon Plan 10X objective, 111 photos in stack with 6 um steps. [bw] "Having found bastnaesite twice now in two different Hurricane localities, I don't think it can be too awfully uncommon. It certainly doesn't show up as much as zircon, but with persistence and a micro hunter attitude, it should be found. I think most people that go to Hurricane are just looking for the typical species that make nice thumbnails."
GLAUCONITE A variety of Celadonite Hurricane Mtn., Conway, NH 2 cm specimen. Glauconite on microcline	Species: GLAUCONITE A variety of Celadonite Locality: Hurricane Mtn., Conway, NH Specimen Size: 2 cm specimen. Glauconite on microcline Field Collected: Peter Samuelson - 1976 Catalog No.: A Gordon Jackson specimen Notes: Glauconite is essentially the K-deficient equivalent of celadonite. Mindat/org states "For practical purposes, if the mineral occurred in a sedimentary rock it was called 'glauconite' and if in a volcanic rock it was called 'celadonite'.� [tm] This does not seem to be the case here. Bishop et. al. in their 2008 article in Clay Minerals (3/ 2008) include an analysis of a Hurricane Mtn. glauconite with a formula: Na_0.03K_0.753(Ti_0.003Al_0.202Fe³⁺_1.426Fe²⁺_0.402Mg_0.004)(Si_3.541Al_0.549)O₁₀(OH)₂ .
GLAUCONITE A variety of Celadonite Hurricane Mtn., Conway, NH 3.5 cm specimen of massive, amorphous, Glauconite	Species: GLAUCONITE A variety of Celadonite Locality: Hurricane Mtn., Conway, NH Specimen Size: 3.5 cm specimen of massive, amorphous, Glauconite Field Collected: Gordon Jackson Catalog No.: 1681 Notes: In February, 2019, a polished grain EDS analysis on a sample from this specimen indicated a celadonite group mineral. Presently, magnesium is an "essential element" for glauconite, (per mindat.org). No magnesium was detected in my analysis. A PXRD of Hurricane Mtn. glauconite was obtained from a sample submitted to John Attard's XRD service. This PXRD plot is a good match for glauconite.
GLAUCONITE A variety of Celadonite Hurricane Mtn., Conway, NH 3 cm specimen of massive, amorphous, Glauconite	Species: GLAUCONITE A variety of Celadonite Locality: Hurricane Mtn., Conway, NH Specimen Size: 3 cm specimen of massive, amorphous, Glauconite Field Collected: Catalog No.: A Harvard Museum specimen Notes: A Kevin Czaja photo
HEMATITE Hurricane Mtn., Conway, NH 2.8 cm - full specimen HEMATITE Hurricane Mtn., Conway, NH 1.5 cm - zoom view HEMATITE Hurricane Mtn., Conway, NH 7 mm field of view	Species: HEMATITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 2.8 cm - full specimen Field Collected: Don Swenson Catalog No.: u2040 - 3rd photo Notes: When I first saw these lustrous black crystals I thought they might be cassiterite. However an EDS analysis showed them to be hematite. The small bit of silica is likely an impurity in the sample.
HEMATITE Hurricane Mtn., Conway, NH 1.54 mm crystal	Species: HEMATITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 1.54 mm crystal Field Collected: Bob Wilken - 9/21 Catalog No.: A Bob Wilken specimen & photo. HUR-Hematite01A Notes: Visual identification by Bob. Might also be ilmenite
HEMATITE on Zircon Hurricane Mtn., Conway, NH 0.3 mm hematite crystal on a zircon crystal	Species: HEMATITE on Zircon Locality: Hurricane Mtn., Conway, NH Specimen Size: 0.3 mm hematite crystal on a zircon crystal Field Collected: Bob Wilken Catalog No.: u2643 Notes:
HEMATITE Hurricane Mtn., Conway, NH 0.5 mm hematite crystals	Species: HEMATITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 0.5 mm hematite crystals Field Collected: Bob Wilken Catalog No.: Notes:
HEMATITE Hurricane Mtn., Conway, NH 0.5 mm hematite crystal	Species: HEMATITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 0.5 mm hematite crystal Field Collected: Bob Wilken Catalog No.: Notes:
MICROCLINE Hurricane Mtn., Conway, NH 4 cm specimen	Species: MICROCLINE Locality: Hurricane Mtn., Conway, NH Specimen Size: 4 cm specimen Field Collected: Tom Mortimer Catalog No.: Notes: Microcline crystals are common in Hurricane miarolitic cavities.
MICROCLINE Hurricane Mtn., Conway, NH 3.5 cm specimen	Species: MICROCLINE Locality: Hurricane Mtn., Conway, NH Specimen Size: 3.5 cm specimen Field Collected: Tom Mortimer Catalog No.: 2026 Notes: These microcline crystals have a manganese (pyrolucite ?) or iron-oxide coating, demonstrating that external color can sometimes be a poor aid to species identification. The matrix is quartz, feldspar and arfvedsonite.
OPAL var. Hyalite Hurricane Mtn. Conway, NH 10 mm field of view	Species: OPAL var. Hyalite Locality: Hurricane Mtn. Conway, NH Specimen Size: 10 mm field of view Field Collected: Leroy Grant - early '70's Catalog No.: NC Notes: A voucher specimen for hyalite opal on Hurricane Mtn. A no stacking photo. This hyalite has a bright green fluorescence in SW UV.
QUARTZ Hurricane Mtn. Conway, NH 9.5 cm smoky crystal	Species: QUARTZ Locality: Hurricane Mtn. Conway, NH Specimen Size: 9.5 cm smoky crystal Field Collected: R. Bohmar 1972 Catalog No.: Harvard Mineral Museum #124880. Notes:
QUARTZ Hurricane Mtn. Conway, NH 2.5 mm field of view	Species: QUARTZ Locality: Hurricane Mtn. Conway, NH Specimen Size: 2.5 mm field of view Field Collected: Leroy Grant - 1970's Catalog No.: NC Notes:
RHYOLITE with cabochon Hurricane Mtn. Conway, NH 91.9 ct. oval with typical rough	Species: RHYOLITE with cabochon Locality: Hurricane Mtn. Conway, NH Specimen Size: 91.9 ct. oval with typical rough Field Collected: Catalog No.: Harvard Mineral Museum Gem #1404 Notes: A Kevin Czaja photo. Rhyolite is a feldspar-quartz mixture.
RIEBECKITE Hurricane Mtn., Conway, NH 12 mm field of view	Species: RIEBECKITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 12 mm field of view Field Collected: Tom Mortimer Catalog No.: 576 Notes: I have wondered for many years if these black hair specimens (I collected many) are arfvedsonite, riebeckite, or perhaps aegirine. All are possibilities from the Hurricane Mtn. locality. A qualitative EDS analysis did not resolve the ambiguity (the sodium response of EDS detector is low and not indicative of the true sodium proportion). Both arfvedsonite and riebeckite have a Fe:Si ratio of 5:8. Aegrine is lower, 4:8 (1:2). The plot appears to support a 5:8 ratio. A review of two articles in volume 34 of the Canadian Mineralogist indicates this fibrous amphibole is riebeckite: http://rruff.info/doclib/cm/vol34/CM34_1011.pdf by Foord et. al.: "The fine-grained riebeckite is a product of final low-temperature hydrothermal solutions that were present in the miarolitic cavities." and http://rruff.info/doclib/cm/vol34/CM34_1015.pdf by Hawthorne et. al. "fibrous Li-poor riebeckite partly fills some of the miarolitic cavities" A 16 image stack processed with Helicon Focus.
RIEBECKITE Hurricane Mtn., Conway, NH 7 cm specimen with large zone of blue riebeckite var crocidolite.	Species: RIEBECKITE var Crocidolite Locality: Hurricane Mtn., Conway, NH Specimen Size: 7 cm specimen with large zone of blue riebeckite var crocidolite. Field Collected: Tom Mortimer (1982) Catalog No.: 178 Notes:
RIEBECKITE Hurricane Mtn., Conway, NH 4 cm specimen with zone of blue riebeckite var crocidolite.	Species: RIEBECKITE var Crocidolite Locality: Hurricane Mtn., Conway, NH Specimen Size: 4 cm specimen with zone of blue riebeckite var crocidolite. Field Collected: Tom Mortimer (1982) Catalog No.: Notes:
RIEBECKITE Hurricane Mtn., Conway, NH 2.2 cm specimen with acicular black hairs of riebeckite	Species: RIEBECKITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 2.2 cm specimen with acicular black hairs of riebeckite Field Collected: Tom Mortimer (1982) Catalog No.: Notes:
RIEBECKITE North Moat Mtn., Bartlett, NH 2 cm mass of fibrous riebeckite	Species: RIEBECKITE Locality: North Moat Mtn., Bartlett, NH Specimen Size: 2 cm mass of fibrous riebeckite Field Collected: Gene Bearss (1985) Catalog No.: A Gene Bearss collection specimen Notes: Identification by Gene Bearss.
RIEBECKITE Hurricane Mtn., Conway, NH 1.6 cm terminated crystal. RIEBECKITE Hurricane Mtn., Conway, NH 1.6 cm terminated crystal	Species: RIEBECKITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 1.6 cm terminated crystal, front and back views Field Collected: Unknown - A purchased specimen - 8/15 Catalog No.: 1964 Notes: When purchased, this TN specimen was labeled as arfvedsonite. However the scratched surface is pale blue (visible, second photo), suggesting riebeckite. An XRD analysis - arfvedsonite correlation had a slightly better correlation with arfvedsonite than with riebeckite XRD analysis - riebeckite correlation . This suggests an arfvedsonite crystal altering to riebeckite.
RIEBECKITE var. Crocidolite Hurricane Mtn., Conway, NH 2.2 cm field of view	Species: RIEBECKITE var. Crocidolite Locality: Hurricane Mtn., Conway, NH Specimen Size: 2.2 cm field of view Field Collected: Leroy Grant -1970's Catalog No.: u2371 Notes: Mat of blue crocidolite on smoky quartz crystal with astrophyllite..
SIDERITE Hurricane Mtn., Conway, NH 2.5 cm specimen. Group of flattened rhombic siderite crystals at juncture of crossed arfvedsonite crystals.	Species: SIDERITE Locality: Hurricane Mtn., Conway, NH Specimen Size: 2.5 cm specimen. Group of flattened rhombic siderite crystals at juncture of crossed arfvedsonite crystals. Field Collected: Tom Mortimer Catalog No.: U083 Notes:
THORITE Var. Thorogummite Hurricane Mtn. Conway, NH 0.9 mm tabular crystal	Species: THORITE Var. Thorogummite Locality: Hurricane Mtn. Conway, NH Specimen Size: 0.9 mm tabular crystal Field Collected: Bob Wilken 2022 Catalog No. The carbon tape sample: Notes: An EDS analyses indicated thorogummite.
THORITE Var. Thorogummite Hurricane Mtn. Conway, NH 1.3 mm field of view	Species: THORITE Var. Thorogummite Locality: Hurricane Mtn. Conway, NH Specimen Size: 1.3 mm field of view Field Collected: Bob Wilken 2022 Catalog No.: Harvard Mineral Museum specimens #151082. Notes: An EDS analyses indicated these red-brown tablets are thorite var. thorogummite. Fe, P and Al are known substitutions in thorogummite. A second EDS analyses by Al Falster at the MMGM laboratory also indicated thorogummite.
THORITE Var. Thorogummite Hurricane Mtn. Conway, NH Largest sample is 6.5 cm THORITE Var. Thorogummite Hurricane Mtn. Conway, NH 4.5 cm specimen THORITE Var. Thorogummite Hurricane Mtn. Conway, NH 2 cm field of view	Species: THORITE Var. Thorogummite Locality: Hurricane Mtn. Conway, NH Specimen Size: Largest sample is 6.5 cm Field Collected: E. Schlichter - 1982 Catalog No.: Harvard Mineral Museum specimens #151082. Notes: Top photo by Kevin Czaja. Thorogummite was discredited as a valid species in 2014. A poly bag of these was loaned from the Harvard collection for photos and to supply grains for analysis. The most radioactive specimen is shown in the second photo with a close-up in the third photo. The resinous brown area on the specimen right side is suspected to be the source for the strong radioactive response. An EDS analyses by Al Falster at the MMGM laboratory indicated thorite variety thorogummite.
ZIRCON Hurricane Mtn., Conway, NH 2 mm zircon crystal embedded in arfvedsonite hairs	Species: ZIRCON Locality: Hurricane Mtn., Conway, NH Specimen Size: 2 mm zircon crystal embedded in arfvedsonite hairs Field Collected: Tom Mortimer Catalog No.: u011 Notes:
ZIRCON Hurricane Mtn., Conway, NH Zircon crystals to 1 mm on albite	Species: ZIRCON Locality: Hurricane Mtn., Conway, NH Specimen Size: Zircon crystals to 1 mm on albite Field Collected: Tom Mortimer Catalog No.: u109 Notes:
ZIRCON Hurricane Mtn., Conway, NH Zircon crystals (largest 3 mm) on microcline with limonite crust coating	Species: ZIRCON Locality: Hurricane Mtn., Conway, NH Specimen Size: Zircon crystals (largest 3 mm) on microcline with limonite crust coating Field Collected: Tom Mortimer Catalog No.: Notes:
ZIRCON Hurricane Mtn., Conway, NH 3 mm zircon crystal (side view) on microcline with arfvedsonite (black) ZIRCON Hurricane Mtn., Conway, NH 3 mm zircon (c axis view) crystal on microcline with arfvedsonite (black)	Species: ZIRCON Locality: Hurricane Mtn., Conway, NH Specimen Size: 3 mm zircon crystal on microcline with arfvedsonite (black), two views Field Collected: Tom Mortimer Catalog No.: 577 Notes: C axis view is a 19 image stack.
ZIRCON Hurricane Mtn, Conway, NH 3.5 mm crystal	Species: ZIRCON Locality: Hurricane Mtn, Conway, NH Specimen Size: 3.5 mm crystal Field Collected: Tom Mortimer Catalog No.: Not Cataloged Notes: These Hurricane Mtn. zircons have only a very pale yellow fluorescence in SW UV.
ZIRCON Huricane Mtn., Conway, NH 1.2 cm zircon	Species: ZIRCON Locality: Huricane Mtn., Conway, NH Specimen Size: 1.2 cm zircon Field Collected: Roger Eastman Catalog No.: A Don Dallaire specimen and photo. Acquired 8/22.
ZIRCON Huricane Mtn., Conway, NH 2.7 cm specimen	Species: ZIRCON Locality: Huricane Mtn., Conway, NH Specimen Size: 2.7 cm specimen Field Collected: Roger Eastman Catalog No.: A Don Dallaire specimen and photo. Acquired 8/22. A bit of arfvedsonite is present on the left side of the specimen.
ZIRCON Hurricane Mtn., Conway, NH 2.0 mm field of view	Species: ZIRCON Locality: Hurricane Mtn., Conway, NH Specimen Size: 2.0 mm field of view Field Collected: Bob Wilken, 2022. Catalog No.: u2643 Notes: