“Calcite crystals to 9 cm have been overgrown with brown siderite, all on crystalline quartz matrix. The siderite appears to have been deposited in stages, because the tip of one of the overgrown calcite crystals has either been broken or etched away revealing layers of siderite that have undergone selective dissolution.”

“Calcite crystals to 9 cm have been overgrown with brown siderite, all on crystalline quartz matrix. The siderite appears to have been deposited in stages, because the tip of one of the overgrown calcite crystals has either been broken or etched away revealing layers of siderite that have undergone selective dissolution.”