Spurrite

spurrites

dellaite

merwinite

monticellite

Images

Formula: Ca5(SiO4)2(CO3)
Nesosilicate (insular SiO4 groups)
Specific gravity: 3
Hardness: 5
Streak: white
Colour: colourless, grey-white, lilac-grey
Environments:

Metamorphic environments

Spurrite is a common component of magnesian skarn at the contact zone between limestone and diorite.

Alteration

dellaite and calcite to spurrite and H2O
2Ca6(Si2O7)(SiO4)(OH)2 + 3CaCO3 ⇌ 3Ca5(SiO4)2(CO3) + 2H2O
Higher temperatures favour the forward reaction (MM 34.1.1-16).

monticellite and spurrite to merwinite and calcite
2CaMg(SiO4) + Ca5(SiO4)2(CO3) ⇌ 2Ca3Mg(SiO4)2 + CaCO3

monticellite, spurrite and quartz to merwinite and CO2
5CaMg(SiO4) + Ca5(SiO4)2(CO3) + SiO2 ⇌ 5Ca3Mg(SiO4)2 + 2CO2

tilleyite to spurrite and CO2
Ca5Si2O7(CO3)2 ⇌ Ca5(SiO4)2(CO3) + CO2
At higher temperatures favour the forward reaction (MM 34.1.1-16).

wollastonite and spurrite to rankinite and CO2
4CaSiO3 + Ca5(SiO4)2(CO3) ⇌ 3Ca3Si2O7 + CO2
Higher temperatures favour the forward reaction (MM 34.1.1-16).

Back to Minerals