26:
532:
is 04.DB.15a, since the metal:oxygen ratio is around 1:2 and the mineral has medium-sized cations; chains of edge-sharing octahedra. Other elements in the
Ramsdellite / 04.DB.15 group are
668:
313:
as a professional mineralogist. Ramsdellite was one of the new phases he first recognized in the "black manganese oxide" minerals. It was later named in his honour by
839:
297:
manganese dioxide mineral. It is relatively uncommon, and is usually found in deposits containing other manganese oxide crystals.
573:
640:
963:
529:
314:
83:
953:
568:, and is often found in deposits containing various other manganese oxides. The mineral is relatively rare. The
927:
958:
423:
204:
240:
364:
342:
294:
108:
600:
93:
580:, US. Other locations in the USA where well-characterized samples of Ramsdellite have been found are
577:
317:
and W. E. Richmond, who fully described the mineral in 1943. The mineral is also called
Groutellite.
631:, Black Forest; in Egypt at Gebel To Yu, Yoider, and Um Bogna; and in South Africa at Hotazel, near
968:
585:
569:
73:
31:
310:
306:
823:
337:, but is orthorhombic where pyrolusite is tetragonal. Ramsdellite belongs to the Orthorhombic
413:
194:
181:
874:
891:
8:
644:
593:
589:
581:
469:
459:
230:
220:
825:
Manganese
Reserves and Resources of the World and Their Industrial Implications: Report
787:
690:
403:
171:
694:
620:
608:
680:
250:
55:
604:
533:
799:
777:
775:
773:
354:
338:
103:
48:
947:
708:
706:
704:
564:
Ramsdellite is formed by oxidization of weathered manganese minerals such as
390:
161:
115:
838:
793:
770:
624:
143:
737:
701:
528:). The Hey's CIM Ref is 7.18.8 (Oxides and Hydroxides, Oxides of Mn). The
648:
628:
541:
508:
378:
125:
685:
910:
856:
487:
334:
186:
25:
635:, Northern Cape. Ramsdellite is found in the manganese deposits near
612:
565:
616:
382:
760:
758:
756:
754:
752:
727:
725:
723:
721:
890:
821:
805:
781:
632:
549:
260:
213:
615:, South Australia; in Japan in the Otoshibetsu and Tanno mines,
926:
909:
749:
743:
718:
712:
636:
599:
Good samples have been found in Canada along the East River in
454:
Steel-gray to iron-black; yellowish white in reflected light.
572:, the place where Ramsdellite was first identified, is the
309:(1895–1975). Ramsdell spent almost all his career at the
611:, Maharashtra; in Australia in the Iron Monarch quarry,
333:. Ramsdellite has the same chemistry as the more common
305:
Ramsdellite is named after the
American mineralogist,
524:
The Dana classification is 4.4.7.1 (simple oxides: AX
873:
855:
764:
731:
513:Pbnm. a = 4.533(5) b = 9.27(1) c = 2.866(5) Z = 4
945:
794:Nickel-Strunz Oxides Classification – webmineral
320:
30:Sample from Mistake Mine, Box Canyon District,
639:, Haut-Ogooué Province, Gabon, mined by the
325:The chemical formula for Ramsdellite is MnO
822:National Materials Advisory Board (1981),
408:Prominent, on three pinacoids and a prism
24:
684:
436:Measured = 4.65–4.83 Calculated = 4.84
946:
806:National Materials Advisory Board 1981
840:"Nickel-Strunz Oxides Classification"
782:Ramsdellite – Mineral Data Publishing
669:"IMA–CNMNC approved mineral symbols"
666:
744:Willett F. Ramsdell – U of Michigan
713:The Mineral Ramsdellite – galleries
13:
623:; in Germany at BĂĽtten-Adenstadt,
273:NCalc= 2.89 (Dcalc) / 2.72 (Dmeas)
166:Granular / Massive-Fibrous / Platy
14:
980:
519:
863:, Hudson Institute of Mineralogy
643:. These deposits were formed by
828:, National Academies, NAP:11507
559:
329:. The empirical formula is MnO
660:
607:; In India in Dongari Buzurg,
603:; in Mexico in Los Gavilanes,
592:; and Monroe-Tener mine, near
464:Black, may have brownish tint
1:
641:Compagnie minière de l'Ogooué
321:Chemistry and crystallography
156:Iron black, Black, Steel gray
148:86.94 gm (Mn 63.19% O 36.81%)
932:, The University of Michigan
530:Nickel–Strunz classification
7:
619:; in the Czech Republic at
10:
985:
964:Minerals in space group 62
875:"Ramsdellite Mineral Data"
814:
601:Pictou County, Nova Scotia
395:Platy, fibrous or massive
911:"The Mineral Ramsdellite"
899:, Mineral Data Publishing
584:, Arizona; Mistake mine,
578:Sierra County, New Mexico
440:
399:
350:
277:
269:
259:
249:
239:
229:
219:
203:
193:
180:
170:
160:
152:
142:
137:
124:
114:
102:
92:
82:
72:
54:
44:
39:
23:
18:
765:Ramsdellite – mindat.org
732:Ramsdellite Mineral Data
654:
586:Yavapai County, Arizona
300:
32:Yavapai County, Arizona
954:Manganese(IV) minerals
673:Mineralogical Magazine
311:University of Michigan
307:Lewis Stephen Ramsdell
255:4.79 g/cm (calculated)
959:Orthorhombic minerals
627:and Clara Mine, near
588:; Idarado mine, near
424:Hardness (Mohs scale)
84:Strunz classification
492:Strong; pale yellow
474:Brilliant metallic.
265:4.37 g/cm (measured)
929:Willett F. Ramsdell
686:10.1180/mgm.2021.43
667:Warr, L.N. (2021).
590:Telluride, Colorado
582:Artillery Mountains
94:Dana classification
270:Optical properties
517:
516:
315:Michael Fleischer
284:
283:
976:
939:
938:
937:
923:
922:
921:
906:
905:
904:
898:
887:
886:
885:
870:
869:
868:
852:
851:
850:
835:
834:
833:
809:
803:
797:
791:
785:
779:
768:
762:
747:
741:
735:
729:
716:
710:
699:
698:
688:
664:
348:
347:
341:and Dipyramidal
251:Specific gravity
209:
61:
60:(repeating unit)
28:
16:
15:
984:
983:
979:
978:
977:
975:
974:
973:
944:
943:
942:
935:
933:
919:
917:
902:
900:
896:
883:
881:
866:
864:
848:
846:
831:
829:
817:
812:
804:
800:
792:
788:
780:
771:
763:
750:
742:
738:
730:
719:
711:
702:
665:
661:
657:
605:Baja California
562:
555:
552:: (Mn,Mn)(O,OH)
547:
539:
534:Paramontroseite
527:
522:
332:
328:
323:
303:
292:
207:
67:
59:
58:
35:
12:
11:
5:
982:
972:
971:
969:Oxide minerals
966:
961:
956:
941:
940:
924:
907:
888:
879:webmineral.com
871:
853:
844:webmineral.com
836:
818:
816:
813:
811:
810:
808:, p. 178.
798:
786:
769:
748:
736:
717:
700:
679:(3): 291–320.
658:
656:
653:
647:enrichment of
561:
558:
553:
545:
537:
525:
521:
520:Classification
518:
515:
514:
511:
506:
502:
501:
498:
494:
493:
490:
484:
483:
480:
476:
475:
472:
466:
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456:
455:
452:
448:
447:
445:
442:
438:
437:
434:
430:
429:
426:
420:
419:
416:
410:
409:
406:
401:
397:
396:
393:
387:
386:
375:
371:
370:
367:
361:
360:
357:
352:
345:. Properties:
339:crystal system
330:
326:
322:
319:
302:
299:
290:
282:
281:
279:
275:
274:
271:
267:
266:
263:
257:
256:
253:
247:
246:
243:
237:
236:
235:Brownish black
233:
227:
226:
223:
217:
216:
210:
201:
200:
197:
191:
190:
184:
178:
177:
174:
168:
167:
164:
158:
157:
154:
150:
149:
146:
140:
139:
138:Identification
135:
134:
128:
122:
121:
118:
112:
111:
106:
104:Crystal system
100:
99:
96:
90:
89:
86:
80:
79:
76:
70:
69:
65:
62:
52:
51:
49:Oxide minerals
46:
42:
41:
37:
36:
29:
21:
20:
9:
6:
4:
3:
2:
981:
970:
967:
965:
962:
960:
957:
955:
952:
951:
949:
931:
930:
925:
916:
915:galleries.com
912:
908:
895:
894:
889:
880:
876:
872:
862:
858:
857:"Ramsdellite"
854:
845:
841:
837:
827:
826:
820:
819:
807:
802:
795:
790:
783:
778:
776:
774:
766:
761:
759:
757:
755:
753:
745:
740:
733:
728:
726:
724:
722:
714:
709:
707:
705:
696:
692:
687:
682:
678:
674:
670:
663:
659:
652:
650:
646:
642:
638:
634:
630:
626:
622:
618:
614:
610:
606:
602:
597:
596:, Minnesota.
595:
591:
587:
583:
579:
575:
571:
570:type locality
567:
557:
551:
543:
535:
531:
512:
510:
507:
504:
503:
499:
497:Bireflectance
496:
495:
491:
489:
486:
485:
481:
479:Optical Class
478:
477:
473:
471:
468:
467:
463:
461:
458:
457:
453:
450:
449:
446:
443:
439:
435:
432:
431:
427:
425:
422:
421:
417:
415:
412:
411:
407:
405:
402:
398:
394:
392:
391:Crystal habit
389:
388:
384:
380:
376:
373:
372:
368:
366:
363:
362:
359:Orthorhombic
358:
356:
353:
349:
346:
344:
343:crystal class
340:
336:
318:
316:
312:
308:
298:
296:
288:
280:
276:
272:
268:
264:
262:
258:
254:
252:
248:
244:
242:
238:
234:
232:
228:
224:
222:
218:
215:
211:
206:
202:
198:
196:
192:
188:
185:
183:
179:
175:
173:
169:
165:
163:
162:Crystal habit
159:
155:
151:
147:
145:
141:
136:
132:
129:
127:
123:
119:
117:
116:Crystal class
113:
110:
107:
105:
101:
97:
95:
91:
87:
85:
81:
77:
75:
71:
63:
57:
53:
50:
47:
43:
38:
33:
27:
22:
17:
934:, retrieved
928:
918:, retrieved
914:
901:, retrieved
892:
882:, retrieved
878:
865:, retrieved
860:
847:, retrieved
843:
830:, retrieved
824:
801:
789:
739:
676:
672:
662:
625:Lower Saxony
621:Hornà Blatná
598:
576:district in
563:
560:Distribution
523:
488:Anisotropism
379:pseudomorphs
369:2/m 2/m 2/m
324:
304:
295:orthorhombic
286:
285:
144:Formula mass
130:
109:Orthorhombic
893:Ramsdellite
651:sediments.
649:Precambrian
629:Oberwolfach
574:Lake Valley
542:Akhtenskite
509:Space group
365:Point group
287:Ramsdellite
241:Diaphaneity
126:Space group
120:Dipyramidal
98:04.04.07.01
19:Ramsdellite
948:Categories
936:2017-12-22
920:2017-12-19
903:2017-12-22
884:2017-12-19
867:2017-12-22
861:mindat.org
849:2017-12-22
832:2017-10-24
548:(15b) and
500:Distinct.
335:pyrolusite
278:References
205:Mohs scale
187:Conchoidal
74:IMA symbol
695:235729616
645:supergene
613:Iron Knob
566:manganite
385:crystals
189:to uneven
88:04.DB.15a
64:MnO2 (MnO
617:Hokkaido
609:Bhandara
594:Chisholm
482:Biaxial
428:About 3
418:Brittle
414:Tenacity
404:Cleavage
400:Physical
383:groutite
293:) is an
225:Metallic
208:hardness
195:Tenacity
182:Fracture
172:Cleavage
133:(no. 62)
45:Category
815:Sources
633:Kuruman
556:(15c).
550:Nsutite
544:: ε-MnO
540:(15a),
441:Optical
351:Crystal
261:Density
214:Calcite
199:Brittle
56:Formula
40:General
693:
637:Moanda
470:Luster
460:Streak
444:Opaque
377:Often
355:System
245:Opaque
231:Streak
221:Luster
897:(PDF)
691:S2CID
655:Notes
451:Color
153:Color
34:, USA
536:: VO
505:Cell
374:Form
301:Name
289:(MnO
212:3 –
176:Good
131:Pbnm
681:doi
381:of
78:Rmd
950::
913:,
877:,
859:,
842:,
772:^
751:^
720:^
703:^
689:.
677:85
675:.
671:.
796:.
784:.
767:.
746:.
734:.
715:.
697:.
683::
554:2
546:2
538:2
526:2
433:D
331:2
327:2
291:2
68:)
66:2
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