[3201] “Rainbow.” Opinion seems divided as to whether this is Hyalin quartz iridized internally, or prismatic crystals of Limpid quartz, which decompose the rays of the sun.

[3202] The reading and meaning of this passage are very doubtful.

[3203] The reading is doubtful, “zeros” and “erros” being given by some MSS. Ajasson hazards a conjecture that it may have been a variety of quartz, formed of a concretion of agates united by a cement of a similar nature.

[3204] A general name for Agate, and possibly some other stones not now included under the name.

[3205] “Jasper agate.”

[3206] “Wax agate.” The modern Orange agate, probably.

[3207] “Smaragdus agate.” Emerald-coloured agate.

[3208] “Blood agate.” Agate sprinkled with spots of red jasper.

[3209] “White agate.”

[3210] “Tree agate.” Moss agate or Mocha stone, coloured by oxide of iron.