A Technique for Labeling Rock and Mineral Specimens

Michael A. Gorycki, Ph.D. 

First posted: November 31, 2007

                                        Updated; June 6, 2017                   

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 clear nail polish 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 micro-mounts. 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 catalogues or 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, affixed directly to each specimen, that supply adequate, complete data for each sample. 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, have the distinct advantage of also promoting 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 used to apply labels to hand specimens have been tested. The best to use are slow-setting, low-viscosity, optically clear, colorless, non-yellowing types. Unfortunately, clear epoxy plastics tend to yellow over time. EukittÆ (see Google) works well, as does clear nail polish such as “Sally Hansen Hard as Nails Nail Color, Crystal Clear”. The nail polish is inexpensive and convenient. Both do not undergo a noticeable change in volume as they solidify. 

The specimens are first arranged with their respective labels. Using forceps, each label is dipped in, or coated with the adhesive 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. The adhesive adheres firmly to polished specimen surfaces if the surfaces have been well-cleaned and dried. 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 (Figs. 1-3).

Fig. 1. Rock specimen with embedded label.

Fig. 2. A close-up view of the rock specimen label seen in Fig. 1. The label is 17 mm wide and bears a 0.5 mm high font. Omm refers to the geologic symbol for this formation on the NY State map.

Figure 3. A micro-mount rock specimen glued to a slide for study in a dissecting microscope. 

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, EukittÆ coated labels may be removed using xylene, and nail polish with nail polish remover. 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, micro-mount 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 micro-mount 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.

Update: Since the publishing of this paper in 2007, I’m pleased to see the interest shown in the proper labeling of rocks and minerals by the large number of entries posted on the internet.

REFERENCES CITED

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.

Any questions or comments can be directed to me at: gorycki@yahoo.com