A Technique for
Labeling Rock and Mineral Specimens
Michael A.
Gorycki, Ph.D.
ABSTRACT
The labeling of
individual specimens in rock or mineral collections is often a disorganized,
incomplete and nonprofessional process. In the procedure described here, data
for each specimen in a collection is first compiled by word processing using a
system capable of printing a very small font size on heavy paper as neat,
legible, and detailed specimen labels. These small labels are then cut out,
briefly immersed in a clear, slow-setting epoxy resin, and firmly affixed to
the specimens. Labels produced in this fashion are informative, durable and
should lead to more easily studied specimen collections. Labels can also be
prepared and fixed to petrographic slides, permanent grain mounts, and
micromounts. Identical labels of a larger font size can also be prepared and
placed in specimen trays or specimen bags.
INTRODUCTION
As described by
Meeks et al. (1996), mineral and rock collections frequently suffer from
inadequate or incomplete labeling methods and they list a variety of problems
with collections' management. While a typed catalogue of specimens will retain
and convey a good deal of information, specimens may lose their identity and
collections their usefulness if specimens become dissociated from their labels.
Affixing descriptive catalogue numbers on specimens, usually by pen on a
white-painted area, is a first step, but is awkward and can impede the collection’s
use since the employment of such numbers is but an intermediate step in a
sample’s identification and study.
Since collections
can contain complex and scientifically valuable specimens, it is suggested here
that the best solution would be to prepare labels, which supply adequate,
complete data for each sample, to be affixed directly to each specimen. A
number of labeling techniques was attempted, and the following procedure has
been devised. The technique described here produces standardized, small
labels bearing comprehensive, useful amounts of easily read information. These
labels, affixed directly to the specimens to maintain their integrity, also
promote the study of specimens.
PROCEDURE
Using a word
processing system that provides a very small font size and is capable of
distinct printing on heavy paper, a series of descriptive labels for rock and
mineral specimens in a collection can be recorded in columns, stored, printed,
and cut out. Legible specimen labels, with their lower-case letters reduced to
as small as one-half mm in height, are then produced which are affixed to the
specimens.
Various types of
more or less specific information can be included in the labels based on the
purpose of the collection. Depending on the nature of the specimens, the labels
may include varying amounts of information including: 1) a number corresponding
to the specimen number in the catalogue, 2) the rock or mineral name (either
simple or complex) including an I, S, or M designation for igneous, sedimentary,
or metamorphic rocks, 3) the formal formation name or symbol designation taken
from a geologic map, 4) the mineral assemblage present (including percentages),
5) the name of the collection (department name), or the collector, 6) the price
and/or source of the specimen and the date of collection, 7) collection
locality or map coordinates, 8) fossil names (when present), 9) crystal form
(when present) or other physical properties, including crystal or chemical
class and composition, 10) horizon (geologic age), (11) structural orientation
(strike and dip, top and bottom, etc.), and (12) igneous, metamorphic, or
sedimentary structures present, etc.
If a useful joint,
cleavage, fracture, or sawn surface of appropriate size is not present on a
rock or mineral specimen, a flat surface slightly larger than the label should
first be applied to the specimen with a rock saw, wet grinding wheel, or a
hammer and rock chisel. The label can then be applied after the specimen has
first been scrubbed in soapy water, well-rinsed, and dried.
A variety of
adhesives have been tested to apply labels to hand specimens. The best to use
are slow-setting, low-viscosity, optically-clear, colorless, non-yellowing
types. They are, in increasing order of adhesiveness and hardness, EukittÒ (Calibrated Instruments,
The specimens are
first arranged with their respective labels. Using forceps, each label is
dipped in the EukittÒ or uncured resin and placed on the flat, horizontal
surface of the specimen. To facilitate this procedure, it is helpful to orient
specimens in a tray of clean sand so that the flat surface is horizontal.
Orientation of the flat may be facilitated using a small bull's eye bubble
level. The adhesive also embeds the label, coating and protecting its upper
surface. Because the epoxy resin exhibits little or no shrinkage, any voids or
gaps between the rigid label and an irregular surface of a specimen tend to be
filled. The EukittÒ is suitable for specimens with flat surfaces. The
adhesives completely harden over several days at room temperature. Both
adhesives adhere firmly to polished specimen surfaces if the surfaces have been
well-cleaned. The adhesives are relatively hard and the label remains quite
legible in good part due to the whiteness and opacity of the heavy paper used.
The result is a handy, attractive, and informative specimen (Figures 1
and 2). In addition, the adhesives are durable, water-insoluble, are not
degraded by organisms and remain unchanged for exceptionally long periods. If
the specimens are subsequently sectioned in a rock saw, labels would not be
damaged if temporarily protected with adhesive tape.
If it is necessary
to update a label, an epoxied label can be heated with a heat gun and then
cleanly pried from a specimen. EukittÒ coated labels may be
removed using xylene. Also, if the adhesive surface above a label becomes
damaged, applying a thin coating of fresh adhesive again makes the label smooth
and legible.
Descriptive labels
can also be affixed to petrographic thin sections, permanent mineral grain
mounts, micromount specimens which are examined under the stereomicroscope, and
any other type of microscope specimen, slide-boxes or jars.
Small, particulate,
or friable specimens should be stored in heavy-gauge re-sealable polyethylene
bags along with larger-font labels, produced as described here. Small particles
such as sand grains or microfossils can be temporarily or permanently mounted
on labeled adhesive slides (Gorycki, 1998).
DISCUSSION
There are a number
of advantages to this specimen labeling system. Collection catalogues are computer-stored
and can be edited, updated, and printed with ease. The various small font sizes
available allow a relatively large amount of information to be leisurely
entered in word processing on small labels for each specimen. Various font
types, sizes, and symbols can be mixed on the same label. A large number of
specimens can be labeled at one time, and the labels are legible and well
attached to the specimens, but can be removed. They are also informative,
unique to the specimen, durable, editable, replaceable, or repaired. Friable,
particulate, and micromount specimens, petrographic thin-sections, permanent
mineral grain mounts, and any other type of microscope specimen can also be
accommodated. When compared with other direct-specimen labeling procedures,
this technique is not exceptionally labor-intensive and produces reliable,
standardized, easily-read results.
These types of
labels can also be used for other, non-geological specimens or laboratory
items. This labeling technique serves to organize classroom or personal
collections and, importantly, facilitates their study.
REFERENCES CITED
Gorycki, M. A.
1975, Improved adhesions for petrographic thin sections: American Mineralogist,
v. 60, p. 719-721.
Gorycki, M. A. 1998,
Adhesive slides: An improved method for the light microscopy analysis of
particulates and fibers: Microscope, v. 46: no. 3, p. 151-154.
Meeks, L. K.,
Meeks, G. E. and Manger, W. L., 1996, PC-Based Collections Management with GEOLABEL:
Journal of Geoscience Education, v. 44, p. 503-505.
FIGURES 1-3
Figure 1. Rock
specimen with embedded label. Because of minor irregularities in the specimen
surface, the label has been well-attached and is also legible through the use
of an optically clear, colorless, low viscosity, bubble-free, slow-setting,
epoxy resin.
Figure 2. A
close-up view of the rock specimen label seen in Fig. 1. The label is 17 mm
wide and a 0.5 mm high font used. Omm refers to the geologic symbol for this
formation on the
Figure 3. A
micromount rock specimen glued to a slide for study in a dissecting microscope.
The descriptive label has been embedded in, and affixed, using EukittÒ because the slide surface
is flat, adhesion is complete, and the EukittÒ can be used without prior mixing. Use of the solvent
xylene can dissolve the label’s ink causing it to run.
Any questions or
comments can be directed to me at: [email protected]
You are visitor
number:
page counter
Other published
websites by Michael A. Gorycki:
http://www.geocities.com/magsalients/
http://www.geocities.com/ag526/asbestos/asbestos.html
http://www.geocities.com/ag526/muscle/muscle.html