The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1909-05-31
UTAH'S GEM stone
GETS WIDE NOTICE
Amatrice Is Described i'm Recent
Issue of Eastern Mining
Journal.
BEAUTY OF STONE
MAKES 1T DESIRABLE
Geology of Locality Where Gem
Is Found Is Entered
Into.

Recently n gem stone has appeared on
the Salt Lake and eastern jcwclry mar
kets which on account of Its beauty and
individuality is attracting considerable
attention. AmatrIce is essentially n
nlatrix stone. and consists of the min
erals vsriscite and cbalcedony. with
wardite or possibly other hydrous alumi-
mum phosphaies and cryptocrystalline
quartz The amatricc locality was dis
covered in 1905 but until the past year
little development or mining was at
tempted. The frs, locations were made
for copper. but assays showed no copper
present and the claims were abandoned.
Ii is the purpose of the present article
10 briefly describe this new gem material
together With its geological occurrence,
writes T.. X. ZelInsN In the Engineering
and Mining Journal :.
The name "Amatrlcc' was gwen 10 it
by the owners because II Is htt,ngN ue
scriptivc Of the stones. 1t IS derived
from "ma,rice," a synonym for matrlN;
plcfixed by The letter -" Of the word
American 10 denote their American orig
i'm. Tn to date they have been found at
only one locality in Utah. though Naris-
ciic of different type Is found at an
In Mineral Resources" for 1891: six
tecnth annual report OF the United States
geological survey. part 4. page S02' men
lion Is made OF n compact nodular Naris-
cite found in Clay canyon about two
miles south of Mercur. Utah. The name
utahlite was suggested for TINS occur
renee of varisclte, but II is also known
as chor- utahlito. The amatr!cc LOCALITY
is about twenty miles northwest ot Mcr-
cur and Is mentioned under utanlte; III III
Mineral Resources" for 1908. pages ~"
and 1850. as a now occurrence OF this
gem stone The variscitc here however.
differs in It's physical character from that
OF the Clay canyon occurrence, ana part
IN OF this account and also from the tact
that the name 'utahlite" is very similar
found in thc Tintic district. the. name
amatrice vas given 10 the N9llsclte ana
associated minerals. from the locaiity ,s un
der considera ton, The sem Is described
by Dol&las e. Sterrctt in the advance
chapter from Mineral Resources for
1907. pages q and a. under ID IL. the heading
Tooele county, about forty miles south
west of salt Lake CITY and ,n about eishe Sbe
San Pedro, Los Angeles salt Lake Tai,-
road The property lies in The toothlliS
Of the Stansbury rang: on ,ne Ia 6aStern t.nIn
lev The ground slopes from Amstrlce
hili easterly over the old lake bed 'er,,
is a small rounded knob, OF e,,iptlcall
shape with greatest length north and
south. II rises 200 feet above the adla-
cent bench lands on the northwest slds
one-half miles north of Hickman CANYON.
BY barometer the altitude Is o,Oo leel.
farming is done In the neishborhood. NO
water exists on the property, ana az
present IL is hauled distance or sixteen
Thc country rock in the neighhorhood
OF the amatrice deposits is limestone
end quartzite. On the surface inc lme-
stone is a light grayish color With numer-
Gus sltcious and cherty portions Wnich
weather out above the softer stone iorin-
ing Jumps and nodules: Where freshly
broken the rock Is dark blue, Amatrl.c
is found in certain beds OF this cherry
limestone along assures which strike
north 90 degrees west tmagnctic read
lng) and dip 20 To so degrees west.
Northeast of Amatrice hill on the foot
wall side OF the amatrice beds, silicious
limestone appears, but normal limestone
Is again exposed In small gulch. Inc
ground rises from here and the rock be-
comes more slicious going up hill, pass
ing through beds OF granular quartzite
or sandy silicious limestone TO tyPica,
quartzIto at the top OF the rise, a bed
OF the latter outcropS prominently anout
Is feet above the surface and Tor sew
eral hundred feet in length All beds
are conformahle 10 the amatrice-b bearing
limestone. So far no amatrice has been
,ound in the auarlzitc, Along the south
side Of Amatricc hill the limestone Is los,
siliferous. The bedding is we'll exposed
and strikes north 20 degrees west dipping
60 degrees west. Fossils found here
proved to he Of upper carbonifcrous age
Amatrice occurs In a crushed and tTac-
tured zone in the limestone which strikes
approximately parallel 20 the bedding II
appears In places on the outcropS In green
or yellowIsh concretions. Where exposed
In the open-cut workings ii is found In
nodular masses from the size Of pea
10 several inches In diameter. These arc
intimately associated with siliCious ma
tcrial In many cases being ccmcntcd to-
gether in irregular punches and coated
and mixed with chalcedony. The rock
is cut by assures striking north 20 de-
grees west and dipping 40 to so degrees
west. These appear 20 have been the
Undertaking assures and are the strong
est ones noted They show limonlte
staining and in some cases small particles
of fresh pyritc incloscd In a matrice.
ChalcedonY rs one OF the. most abundant
minerals OF the deposits, while fractured
and iron stained ebert is common. \ see
pnd set OF hssurcs striking north 60 de-
yrces east cuts the limestone bedding
az nearly right angles ana dips stccply
- the north: they show no mineralza-
ion. The amatrIce- bearing ground Is OF
United extent Tie gem has been found
only on the eastern slope OF Amatrlcc
nll. over q distance not more than $50
'ect in n north south direction and
roughly estimated $50 feet cast and west.
Development work indicates the deposit
% be OF local origin. No gem In place
or amatrice float has been found 10 the
north OF south. The vertical depth so far
proved has been less than l. feet be-
ncath the surface. but amatTicc has been
found lower down the hill 80 feet ycr-
tically below the present workings.