The natural specimens are rare and of small size (often available only in limited quantity) but often well crystallised while the hydrated cement phases are disordered and cryptocrystalline or amorphous with a poorly defined stoichiometry denoted by the use of dashes in the abbreviations C-S-H and C-A-S-H. Tachanarite (pronunciation as tă·kherenait: /tɑːkɑːrɑːnaɪt/) was named by Sweet et al. (1961) from the Gaelic word "tacharan", a changeling, "an object or a thing left in place of a thing stolen" alluding to the initially presumed instability of this mineral because after the first X-rays photographic examination it was thought to be unstable when exposed to air and prone to decompose into tobermorite and gyrolite.

The results of their study thus contradict these of the very first work of Sweet et al. (1961) reporting the change of tacharanite into a mixture of tobermorite and gyrolite which was the main source of inspiration for the mineral name.

In 2007, on the basis of a larger number of tacharanite samples, a team of mineralogists from the Russian Academy of Sciences at Moscow (Organova et al., 2007) have comprehensively revisited the crystal structure of this poorly studied mineral.

However, the number of oxygen atoms or OH groups present in the hydrate chemical formula can vary, depending on the literature source, and is thus more uncertain, perhaps legitimating the tacharan roots of the name.

[13][14][15][12] This explains the interest of Taylor, Cliff, and their colleagues[6] for reappraising in 1975 the crystal structure and the stability of tachanarite, a decade after the two parallel discoveries in 1961 of the mineral by Sweet et al.[5] at Portree (Isle of Skye, Scotland) and Sutherland[10] in Tasmania.

Tacharanite has received additional attention in the context of natural analogue studies undertaken to investigate the possible effects of an alkaline plume developing around a high-level radioactive waste repository.

The hydroxide anions (OH−) released by the concrete in contact with clay pore water, or granite groundwater, slowly diffuse into the host geological formation where they interact with the various mineral phases of the surrounding rock.

The main reaction products of an alkaline plume in clay are calcium silicate hydrates (C-S-H) and zeolites potentially contributing to clogging the porosity at the cement-clay interface.

As tacharanite is a member of the family of the calcium aluminium silicate hydrates (C-A-S-H), it has also been identified as a potentially newly formed minerals in the frame of the cement–clay interactions and taken into account for the geochemical modelling studies.