A MINERALOGICAL STUDY OF ROSE QUARTZ FROM HOGG MINE, LAGRANGE, GEORGIA WITH A FOCUS ON THE ORIGIN OF ASTERISM AND STRIATIONS WITHIN THE QUARTZ

The Hogg Mine pegmatite contains rose quartz, smoky and white quartz, kaolinite, muscovite, tourmaline, and most notably beryl. The mine is located near LaGrange, Georgia. It was mined for quartz, kaolin, scrap mica, and beryl for beryllium from the 1940’s to 1960’s. The mine is currently open to the public for gem stone collection for a fee. Massive quartz specimens were collected from the Hogg Mine. The rose quartz specimen currently being studied is cross-cut by fractures and has numerous parallel linear striations. There are a few striations that diagonally cross-cut the parallel striations. Before it was cut, the hand sample was originally light pink in color, and was translucent in areas that are not heavily striated. It has since faded to white or colorless. This research is also being performed to determine the source of the pink color of the quartz.

Rose quartz collected from Hogg Mine has been known to show the asterism effect in cut and polished cabochons. Previous research shows that the asterism effect is produced by fibrous inclusions of rutile in minerals such as sapphires and ruby’s, or by a fibrous aluminoborosilicate similar to dumortierite (Rossman, 2006). Another theory is that the striations themselves could be creating the asterism effect if these features are oriented with the same crystallographic structure as the quartz. The pink color may be caused by the same features creating asterism such as fibrous rutile inclusions (Guinel and Norton, 2006) or by an aluminoborosilicate mineral (Goreva et al., 2001).

The specimen has been cut for thin-sections into three different sections, X, Y, and Z, to show different orientations of the striations. To determine the composition of the striations, an elemental traverse via scanning electron microscope (SEM) was performed. There was very minimal chemical variation between the rose quartz matrix and the striations. Based on the results it was decided that the striations are not the product of a mineral inclusion. The striations maybe either fractures that have been in-filled or they are growth lines of crystal faces. The microprobe was used to detect chemical variations within the thin-sections and to determine if the quartz contains fibrous inclusions such as those mentioned by Rossman and others, and to see if there are variations between the striations and the quartz.