An Examination of Red BerylBy FRANK MILEY

Graduate GemologistLos Alamos, New Mexico

Introduction

Red beryl is a gem that has recentlybeen coming into prominence. Wheredoes it come from? How much isavailable? What does it look like?How can it be identified? Recentacquisition of a faceted gem promptedthese questions. After researchingavailable literature and finding verylittle gemological information, it be-came obvious that some personal re-search was to be done on as much redberyl as could be examined.

SourcesRed beryl is only found in three

locations in the United States. Noother sources have been reported. Itoccurs in the Thomas and Wah-WahMountain ranges in Utah I and in theBlack Range in New Mexico 2. Allcrystals are small; the largest crystalsare found in Utah. The Utah materialprovides faceted gemstones that aregenerally less than .5 ct.; commonsizes usually range from .1 ct. to .4 ct.Nearly all faceted gems exhibit a highdegree of internal fractures and inclu-

WINTER 1980-1981

sions. The largest faceted red berylthat has been reported 3 is 2.93 ct.The author has not had the oppor-tunity to see or examine this raregemstone.

In some literature red beryl is listedas bixbite. If you should do a litera-ture survey, you should be aware ofboth names. In this article it is re-ferred to as red beryl.

PropertiesSeveral faceted specimens of the

Utah material were examined for thisreport. New Mexico material was ondisplay- as crystal specimens; it wasmuch too small to be faceted. Thismaterial was not available for micro-scopic examination. It was notedhowever, that the tone and hue werevery close to that of the ThomasMountain material. The Utah mater-ial exhibited differences in transpar-ency, tone, hue, and intensity. Theyare listed as "T" Thomas Mountains,and "W" Wah-Wah Mountains. Theinformation obtained from examin-ing the Utah materials is listed asfollows:

405

Description: "T" Translucent, dark orangy-red of mediumintensity."W" Semitransparent, medium red of highintensity, see Figure 1.Hexagonal.Conchoidal.2.65Fingerprint pattern.Semitransparent to translucent.Polish is vitreous. Fracture is vitreous.1.561(±.001) - 1.569(±.001)

.008Uniaxial.Purplish-red and orangy-red.Inert to both wavelengths.No reaction.No diagnostic spectra.

Crystal character:Fracture:Specific gravity (al:

Characteristic inclusions (b) :

Transparency:Luster:Refracti ve index (c) :

Birefringence:Optic character (d) :

Pleochroism:Ultraviolet fluorescence:Color filter:Absorption spectra (e):

(a) The value of 2.65 was deter-mined by using heavy liquids.The gemstone tested floated in aliquid of 2.67 specific gravity andsank in a liquid of 2.62 specificgravity. The heavy liquid methodwas used because there is a possi-bility for a great variation indetermining the specific gravityon small specimens. The exam-ined specimens were all small,consequently, as a secondarymethod of determination, threefaceted gems were used simultan-eously to determine the specificgravity by the immersion method.The combined weight of the threefaceted gems was .52 ct., and thespecific gravity as determined bythis method was 2.67. The pub-lished value 5 for red and violetberyl lists the specific gravityrange to be 2.77 to 2.87.

(b) Red beryl was highly includedwith secondary inclusions con-sisting of single phase, gas filled,

406

fingerprint patterns, see Figure2. It also contains bizarre shapedhealing voids. Both of these typesof inclusions were in planes orcurved surfaces. There were morefingerprint patterns present thanthe planes of healing voids. Thefingerprint patterns in red berylhave been characteristic. At 20X,straight sided and round inclu-sions were intermixed. At 60X,the straight sided inclusions werepointed and the round 'inclusionsappeared to have short straightsides. At l25X, much smallerinclusions began to appear inbetween the inclusions describedat 60X.

When magnified, all facetedgemstones had one or more in-ternal fractures that extended tothe girdle.

No other inclusions were notedin all specimens examined up tol25X.

(c) A Duplex II Refractometer

GEMS & GEMOLOGY

Figure 1. A 20 ct red beryl from Wah-Wahmountains

wa~ used wit h ~1enoch r«rnru ic

Yellow LIght to determine theretracuve index 01 each gem-stone. lhe pubnshed VLilL1l:~ iorred a nd VIOI<:l beryl lists therefractsve index range at I 585I:t.006) - 1.594 r . mr~l SI neethere was n difference betweenpublished am.! experimemal data.high and low uandurds wereused to check the instrument.The reading ibtained [ut sap-phire was 1.762 1.770 und thereading or quartz was I. 44.

A ienes of readrn g~ were Ib-tained hy rotaung euch gemstonron the hemisphere ol the refrnc-romerer. Rc d ings were nht:li ncoat 0, 45. 90, and 1;1) degreepositions and each was plottedon a chart This 'N<.H done 10

determine I he bl refnngc ace.(d) l'he uniaxial rruerfercnce rig-

LJr~was obta ined usmg the Illurni-nator Polo riscupe set in t he crosspolaroids po .ition. T11<:magnifier[r m the refractometer was in-vcrtcd and placed on tup of 1 he

WJNTER 1980-1981

Figure 2. Fingerprint Inclusions at 36X.dark field

.1nalyzcr i.'I n I ..I small gll:l~s spherewa~ in contac \\ iI h 1 he ~P~C!-men .. Thi5 arra ngcmcnt showc Ithe g.en1~ tll bnve it sbarp uniaxial

Interference iigur e.I he pul lished va luc ! Ior heryl

is umaxial neg •rtrve.(C) r he nu ruberb S Spectroscope

tI lit was used w cheek the gem-~tllne" for the speer roscopic a nal-ysls. -:\0 diagnosuc data was oh-tained from the usc nl this instru-rncnt. The red color was reported J

1l~be caused from the presence ofrnangancso I 1n'~, this has beendetermined bv microprobe' a nul-ysis. The absorption vpcctra I~S[sperfm mcd on the red berv Ispcci-mens that wcr examined did no1

ind icute any tliagnc:;li' ab orpti. n.

PhotographsFigur« t IS a photogra ph of <I. 4.7" :0.

3.05 mm eme ruld ClI1. 2) cr. red berylI rom the Wa h· Wah MUUl1la ins. Fig·ure 11S a photograph of rhc same .20ct. red b F)'!. USing dark Held lightingR.1 3(1:"<.

407

ConclusionIf faceting grade red beryl becomes

more plentiful it should become apopular gemstone. The red hue of theWah- Wah Mountain material resem-bles ruby and ruby red spinel. The redhue of the Thomas Mountain andBlack Range material is slightly darkerand resembles cuprite. Red beryl ishighly included and contains internalfractures, consequently, the durabil-ity should be comparable to highlyincluded emerald and should be usedin protective type mountings.

408

References(I) Ream, Lanny R., The Mineralogical

Record, P. 261, October 1979, TheThomas Range, Wah-Wah Moun-tains And Vicinity, Western Utah.

(2) Kimbler, Frank S. and Haynes, Pa-trick E., New Mexico Geology. P. 15,February, 1980, An Occurrence OfRed Beryl In The Black Range, NewMexico. "

(3) Barlow, F. John, Lapidary Journal,P. 2540, 1979, Red Beryl Of TheWah-Wahs.

(4) New Mexico Minerals Symposium,UNM Campus, Albuquerque, N.M.,September 29, 1979.

(5) Gem Identification Course of theGemological Institute of America.

GEMS & GEMOLOGY