Tourmaline specimens are members of a crystalline silicate mineral group based on boron but influenced by elements including aluminium, iron, magnesium, sodium, lithium, or potassium. Specimens present a wide variety of colours and forms according to the specific mix of these elements. Tourmalines are semi-precious gemstones with many applications, including commercial jewellery production. The word 'tourmaline' derives from the Sinhalese term for the carnelian or red-shaded specimens, "tōramalli".
This specimen has been classified by geologists as 'Black Schoalou/Tourmaline in quartz'. Schoalou may equate to a common black-hued type of Tourmaline associated since around 1400 with mines in Saxony, Germany near a village called Schorl (today's Zchorlau). If this specimen is part of the 'Schorl' species of tourmaline it is a member of the most common group of Tourmalines, a divalent sodium ion influenced group accounting for 95% of specimens.
On assessment, it was noted that the crossed lines (XIs) of this tourmaline have been fractured and rehealed by the quartz matrix in which the tourmaline rests.
This item is significant as an example of its type of gemstone and the geological processes leading to its formation.
A solid medium-sized piece of Black Schoalou/Tourmaline in a cream and peach coloured quartz matrix.
Inscriptions & markings
Black Schoalou / Tourmaline in /
quartz. / Tourmalines XIs have /
been fractured and / rehealed with /
quartz / C. Willman / 15/4/21 /