Dravite Tourmaline
Posted by: Raymond McDougall on 05.04.2023 | Filed under:

Dravite Tourmaline

Specimen # 201216
Mineral: Dravite Tourmaline
Location: Bluegrass Company Quarry (Texas Quarry), Cockeysville, Baltimore, Maryland, USA
Size: 7.9 x 6.0 x 1.7 cm


This is a fascinating specimen, so much so that it inspired John White to write the article “Disjoined Crystals” in  Rocks & Minerals, Vol. 93:3 May/June 2018, pp. 274-275. He refers to this dravite as “by far the classiest example [of disjoined crystals] that I believe I have ever seen.” A disjoined crystal is a cluster or group of crystal fragments that were at one time a continuous crystal but are now separated from each other, separated by a short distance and remaining parallel in orientation. The disjoined brown, lustrous dravite crystal sections in this specimen represent crystals that had formed in the host rock which was then subsequently subjected to physical stresses – dynamothermal metaphorphism. The dravite crystals were stretched and pulled apart, and the host rock recrystallized around the crystal fragments. From the Maryland suite of the John S. White Collection, this specimen is Figure 1 in the article.